LUMINESCENT COMPOUNDS

AND METHODS OF USING SAME

RELATED APPLICATIONS

This application claims the benefit of the filing dates of U.S. Provisional Patent

Applications Nos. 61/780, 123, 61/780,156, and 61/918,804, filed on March 13, 2013, March 13, 2013, and December 20, 2013, respectively, the contents of which are incorporated herein by reference in their entirety. FIELD OF THE INVENTION

The invention relates to compounds having luminescent (e.g., fluorescent, phosphorescent) properties, and to methods of using such compounds. The invention more particularly relates to compounds having photoluminescent and/or electroluminescent properties, and to uses of same. The invention also relates to compounds having photo-receptor properties due to their ability to separate charges and/or photon harvesting properties.

BACKGROUND OF THE INVENTION

Bright and efficient organic light-emitting diode (OLED) devices and

electroluminescent (EL) devices have attracted considerable interest due to their potential application for flat panel displays (e.g., television and computer monitors) and lighting.

OLED based displays offer advantages over the traditional liquid crystal displays, such as: wide viewing angle, fast response, lower power consumption, and lower cost. However, several challenges still must be addressed before OLEDs become truly affordable and attractive next generation display and lighting. To realize white lighting and other full color display applications, it is essential to have the three fundamental colors of red, green, and blue provided by emitters with sufficient color purity and sufficiently high emission efficiency.

Phosphorescent Organic Light-Emitting Diodes (PhOLEDs) have recently received much attention because of their high energy efficiency for next generation flat panel displays and solid state lighting devices. OLEDs based on phosphorescent emitters can have three to four-fold higher device quantum efficiencies than those based on fluorescent emitters. The key challenge in PhOLEDs research is the development of phosphorescent metal complexes with high quantum efficiency and high stability, especially blue phosphorescent compounds. Earlier research efforts on phosphorescent materials for OLEDs focused on 2-phenylpyridine (Hppy)-based Ir(lll) complexes because of their high photoluminescent quantum efficiencies. Although some efficient PhOLEDs based on Ir(lll) emitters have been achieved, stable blue PhOLEDs based on Ir(lll) compounds remain elusive. Phosphorescent compounds are among the most sought-after materials by industry around the world as one of the key color components for electroluminescent devices.

SUMMARY OF THE INVENTION

An aspect of the invention provides a compo of general formula (10):

cyclometallating

ligand

stabilizing

ligand

(10)

wherein a dotted line in a ring indicates that the ring can be saturated, unsaturated, aromatic, or non-aromatic, Y is independently N or O, X is independently C or N and at least one X is N, w is independently 0 to 5, t is 0 or 1 , R ^f , R ⁹ , and R ^h are independently a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, C(R') ₂ , CR'(aryl), C(aryl) ₂ , B(R') ₂ , BR'(aryl), B(aryl) ₂ , aryl-B(aryl) ₂ , O, NR' ₂ , NR'(aryl), N(aryl) ₂ , OR', a nitrile group, C(halo) ₃ which is optionally CF ₃ , or R', where R' is independently an aliphatic group having 1 -24 carbon atoms which may be straight, branched, cyclic, or any combination thereof, substituents are an aliphatic moiety, an aryl moiety, amine, halo, thioether, ether, or any combination thereof; and wherein a substituent can be further substituted; and optionally R is B(substituted- or unsubstituted-aryl) ₂ with the proviso that B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond and with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C ₃ , branched C ₄ , or linear or branched C ₅ -or higher.

Another aspect of the invention provides a compound having general formula (1 ):

wherein R is H, a substituted or unsubstituted aliphatic moiety, halo, a substituted or unsubstituted aryl moiety, or any combination thereof, R is a substituted or unsubstituted aliphatic moiety, a substituted or unsubstituted aryl moiety, or any combination thereof, R ^c is

H, or a substituted or unsubstituted aliphatic moiety, substituted or unsubstituted aryl moiety, or any combination thereof, R is H, a substituted or unsubstituted aliphatic moiety, a substituted or unsubstituted aryl moiety, a substituted or unsubstituted amine, halo, thioether, ether, or any combination thereof, n is a number from 0 to 4; and substituents are an aliphatic moiety, an aryl moiety, amine, halo, thioether, ether, or any combination thereof.

Another aspect of the invention provides a compound having general formula (100):

cyclometallating ligand

stabilizing ligand

(100)

wherein B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond, R is a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, B(R') ₂ , BR'(aryl), B(aryl) ₂ , aryl-B(aryl) ₂ , O, NR' ₂ , OR', a nitrile group, C(halo) ₃ which is optionally CF ₃ , or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof, k, p and h are independently 0 to 5 and m and j are independently 0 to 3, and k, h and m are not all 0, with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C ₃ , branched C ₄ , or linear or branched C ₅ -or higher, t is 0 or 1 , a dotted line in a ring indicates that the ring can be saturated, unsaturated, aromatic, or non-aromatic, X is independently C or N and at least two X are N; and Y is independently N or O, wherein a substituent can be further substituted. In some embodiments, one of the two X that is N is bonded to Pt.

In some embodiments of the above aspects, the cyclometallating ligand comprises a 1 ,2,3-triazolyl moiety, a diphenylmethyl moiety, or an adamantyl moiety. In certain embodiments of the above aspects, the stabilizing ligand comprises a a substituted or unsubstituted 1 ,2,4-triazolyl moiety, a a substituted or unsubstituted /8-diketonato moiety, a a substituted or unsubstituted 1 ,3-diketiminato moiety, a a substituted or unsubstituted picolinato moiety, a substituted or unsubstituted pyridyl moiety, or a a substituted or unsubstituted

In some embodiments of general formula (10), at least one R ^h is a fused ring

In some embodiments of general formula (100) ring 1 is substituted by B(Mes) ₂ . In certain embodiments of general formula (1 ), R ^a is H, t-butyl, CF ₃ , phenyl, benzyl, or any combination thereof. In other embodiments, R ^b is methyl, adamantyl, benzyl, diphenylmethyl or any combination thereof. In still other embodiments, R ^c is H, or methyl. In some embodiments, R ^d is H, methyl, adamantyl, phenyl, benzyl, a substituted or unsubstituted amine, halo, thioether, ether, or any combination thereof. In some embodiments, the compound of general formula (10) is a Pt(ll) complex shown in Table 1. In some embodiments, the compound of general formula (10) is Pt-(Ph2NPh-Bn) (t-Bu-trz) ("T1"), Pt-(Ph2NPh-Bn) (CF ₃ -trz) ("T2"), Pt-(Ph-Bn) (t-Bu-trz) ("T3"), Pt-(Ph-Bn) (CF ₃ -trz) ("T4"), Pt-(Ph-Me) (t-Bu-trz) ("T5"), Pt-(MePh-Bn) (CF ₃ -trz) ("T6"), Pt-(F2Ph-Bn) (t-Bu-trz) ("T7"), Pt-(F2Ph-Bn) (CF ₃ -trz) ("T8"), Pt-(F2Ph-Bn) (t-Bu-trz) ("T9"), Pt-(Ph-Ph ₂ CH)(t-Bu-trz) ("T10"),

Pt-(Ph-Ph ₂ CH)(CF3-trz) ("T11"), Pt-(Ph2NPh-Ph ₂ CH)(t-Bu-trz) ("T12"),

Pt-(Ph2NPh-Ph ₂ CH)(CF ₃ -trz) ("T13"), Pt-(Ph ₃ CPh-Ph ₂ CH)(t-Bu-trz) ("T14"),

Pt-(Ph ₃ CPh-Ph ₂ CH)(CF ₃ -trz) ("T15"), Pt-(Ph ₃ CPh-Bn)(H-trz) ("T16"),

Pt-(Ph ₃ CPh-Ph ₂ CH)(H-trz) ("T17"), or Pt-(Ph3CPh-Bn)(CF3-trz) ("T18").

In other embodiments, the compound of general formula (10) is C1 , C2, C3, C4, C5, C5A, C6, C7, C8, C9, C10, C10A, C10B, C11 , C11A, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21 , C22, C23, C24, C25, C27, C27A, C28, C29, C30, 51 , 52,

Pt(B-triazole1 )(nacnac), Pt(B-triazole2)(nacnac), Pt-9, Pt-12, Pt-110, or Pt-111.

In some embodiments, the compound of general formula (1) has at least one of R ^a'd that is a sterically bulky moiety selected from t-butyl, iso-propyl, adamantyl, diarylamine, or triarylmethyl. In some embodiments, R ^b is diphenylmethyl or benzyl. In certain

embodiments, R ^a is CF ₃ or t-Bu.

An aspect of the invention provides a compound of any one of the above aspects, wherein the compound is photoluminescent or electroluminescent.

An aspect of the invention provides a composition comprising a photoluminescent or electroluminescent compound of any one of the above aspects, an organic polymer, and a solvent.

An aspect of the invention provides an electroluminescent product comprising a compound of any one of the above aspects. The product may be a display device or a lighting device.

An aspect of the invention provides a method of producing electroluminescence, comprising the steps of providing an electroluminescent compound of any one of the above aspects and applying a voltage across said compound so that said compound

electroluminesces.

An aspect of the invention provides an electroluminescent device for use with an applied voltage, comprising a first electrode, a second, transparent electrode, an electron transport layer adjacent the first electrode,

a hole transport layer adjacent the second electrode, and

an emitter which is an electroluminescent compound of any one of the above aspects optionally in a host layer, interposed between the electron transport layer and the hole transport layer,

wherein voltage is applied to the two electrodes to produce an electric field across the emitter so that the emitter electroluminesces.

An aspect of the invention provides a light emitting device comprising an anode, a cathode, and an emissive layer, disposed between the anode and the cathode, wherein the emissive layer comprises a compound of general formula (10). In some embodiments, the emissive layer further comprises a host.

An aspect of the invention provides a consumer product comprising the device of the aspect regarding a light emitting device. In some embodiments of this aspect, the product is a flat panel display device, a flexible display device, a wearable display device, or a lighting device.

An aspect of the invention provides a method of imaging cells, comprising contacting cells with an photoluminescent compound of any one of the above aspects.

An aspect of the invention provides a method for treating a susceptible neoplasm in a mammal in need thereof, said method comprising administering to the mammal a

therapeutically effective amount of a compound according of general formula (10). In an embodiment of this aspect, the compound is administered in combination with another pro-apoptotic agent and/or chemotherapeutic agent, and/or other cancer therapy.

In an embodiment of formula (10), Y is O. In an embodiment of the aspect of formula

(1 ), R is H, t-butyl, CF ₃ , phenyl, benzyl, or any combination thereof. In another embodiment of this aspect, R is methyl, adamantyl, benzyl, diphenylmethyl or any combination thereof.

c d

In an embodiment of this aspect, R is H, or methyl. In yet another embodiment, R is H, methyl, adamantyl, phenyl, benzyl, a substituted or unsubstituted amine, halo, thioether, ether, or any combination thereof. In another embodiment of this aspect, R ^d located para to

a-d the pyridyl ring nitrogen is Me. In an embodiment of this aspect, at least one of R is sterically bulky. In another embodiment of this aspect, the at least one sterically bulky moiety is t-butyl, iso-propyl, adamantyl, diarylamine, or triarylmethyl. In an embodiment of this aspect, on ring 1 in the para position to the 1 ,2,3-triazole ring, R ^d is diphenylamine or triphenylmethyl. In an embodiment of this aspect, on ring 2, R ^b is diphenylmethyl or benzyl. In an embodiment of this aspect, on ring 4, R ^a is CF ₃ or t-Bu.

In another aspect, the invention provides a method of producing electroluminescence including the steps of providing an electroluminescent compound of the second aspect and applying a voltage across said compound so that said compound electroluminesces.

In another aspect, the invention provides an electroluminescent device for use with an applied voltage including a first electrode, an emitter which is an electroluminescent compound of the second aspect optionally in a host layer, and a second, transparent electrode, wherein voltage is applied to the two electrodes to produce an electric field across the emitter so that the emitter electroluminesces.

In yet another aspect, the invention provides an electroluminescent device for use with an applied voltage including a first electrode, a second, transparent electrode, an electron transport layer adjacent the first electrode, a hole transport layer adjacent the second electrode, and an emitter which is an electroluminescent compound of the second aspect optionally in a host layer, interposed between the electron transport layer and the hole transport layer, wherein voltage is applied to the two electrodes to produce an electric field across the emitter so that the emitter electroluminesces.

In another aspect, the invention provides a light emitting device that includes an anode, a cathode, and an emissive layer, disposed between the anode and the cathode, wherein the emissive layer comprises a compound of general formula (10) of the above aspect. In an embodiment of this aspect, the emissive layer further comprises a host.

In yet another aspect the invention provides, a consumer product comprising the device of the previous aspect.

In another aspect, the invention provides methods of making compounds of general formula ( 0) of the above aspect. In an embodiment of this aspect, the invention provides compounds that are photoluminescent or electroluminescent. In an embodiment of this aspect, the compound of general formula (10) is also a compound of general formula (100) and comprises at least two d substituents which are both are located ortho to the boron.

In an embodiment of this aspect, the compound of general formula (10) is also a compound of general formula (100), wherein at least three X are N. In certain embodiments, ring 2 is a triazole. In another embodiment of this aspect, the compound is BC1 or BC2. In another embodiment of this aspect, the compound is a Pt(ll) complex of Table 1 . In an embodiment of this aspect, the compound is C5, BC1 -acac, BC1 -nacnac, BC2-acac, or BC2-nacnac, Pt-12, 51 , 52, Pt(B-NHC1 )(nacnac), Pt(B-NHC2)(nacnac), C1 ,

Pt(B-triazole1 )(nacnac), Pt(B-thazole2)(nacnac), C2, C10, C6, C10A, C7, C10B, C8, C11A, C1 1 , C5A, C4, C3, C12, C9, C13, C27, C14, C15, C28, C16, C29, C17, C30, C18, C27A, C19, C20, C21 , C22, C23, C24, C25, 21 , 22, 23, 24, 25, 10, 1 1 , Pt-9, Pt-1 10, or Pt-1 1 1.

In another aspect the invention provides, the invention provides a compound of general formula (200):

wherein B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond, R is a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, B(R') _2> BR'(aryl), B(aryl) ₂ , aryl-B(aryl) ₂ , O, NR' _2> OR', a nitrile group, C(halo) ₃ which is optionally CF ₃ , or R', where R' is independently an aliphatic group having 1 -24 carbon atoms which may be straight, branched, cyclic, or any combination thereof, k and h are independently 0 to 5, m and j are independently 0 to 3, and k, h and m are not all 0, with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C ₃ , branched C ₄ , or linear or branched C ₅ -or higher, t is 0 or 1 , a dotted line in a ring indicates that the ring can be saturated, unsaturated, aromatic, or non-aromatic, X is independently C or N and at least two X are N; and Y is independently N or O. In an embodiment of this aspect, the compound is photoluminescent or electroluminescent.

In an embodiment of this aspect, the compound is B-NHC1 , B-NHC2, B-triazole1 , B-triazole2, B-Me-triazole1 , B-triazole3, B-triazole4, or B-Me-benzimidazole1.

In another aspect the invention provides, the invention provides a composition comprising a photoluminescent or electroluminescent compound of general formula (10) or (200), an organic polymer, and a solvent.

In another aspect the invention provides a photoluminescent product or an electroluminescent product comprising a compound of the above aspects. In an

embodiment of this aspect, such a product is a flat panel display device or a lighting device. In an embodiment of this aspect, such a product is a luminescent probe or sensor.

In another aspect the invention provides, a method of producing electroluminescence, comprising the steps of: providing an electroluminescent compound of general formula (10) or (200) and applying a voltage across said compound so that said compound

electroluminesces.

In another aspect the invention provides, an electroluminescent device for use with an applied voltage, comprising a first electrode, an emitter which is an electroluminescent compound of general formula (10) or (200) optionally in a host layer, and a second, transparent electrode, wherein voltage is applied to the two electrodes to produce an electric field across the emitter so that the emitter electroluminesces.

In another aspect the invention provides, an electroluminescent device for use with an applied voltage, comprising a first electrode, a second, transparent electrode, an electron transport layer adjacent the first electrode, a hole transport layer adjacent the second electrode, and an emitter which is an electroluminescent compound of general formula (10) or (200) optionally in a host layer, interposed between the electron transport layer and the hole transport layer, wherein voltage is applied to the two electrodes to produce an electric field across the emitter so that the emitter electroluminesces.

In another aspect the invention provides, a method of harvesting photons comprising the steps of: providing a compound of general formula (10) or (200), and providing light such that photons strike said compound and charge separation occurs in said compound.

In some embodiments separated charges recombine and photons are released. In an embodiment separated charges migrate to respective electrodes to produce a potential difference.

In another aspect the invention provides, a method of separating charges comprising the steps of: providing a compound of general formula (10) or (200) and providing light such that photons strike said compound and charge separation occurs in said compound. In some embodiments, separated charges recombine and photons are released.

In an embodiment of this aspect, separated charges migrate to respective electrodes to produce a potential difference.

In another aspect the invention provides, a photocopier employing the above method of harvesting photons or the above method of separating charges.

In yet another aspect the invention provides, a photovoltaic device employing the above method of harvesting photons or the above method of separating charges.

In another aspect the invention provides, a photoreceptor employing the above method of harvesting photons or the above method of separating charges.

In another aspect the invention provides, a solar cell employing the above method of harvesting photons or the above method of separating charges.

In another aspect the invention provides, a semiconductor employing the above method of harvesting photons or the above method of separating charges.

In another aspect the invention provides, a light emitting device comprising an anode, a cathode, and an emissive layer, disposed between the anode and the cathode, wherein the emissive layer comprises a compound of general formula (10) or a compound of general formula (200). In another aspect the invention provides, a consumer product comprising such a device. In another embodiment of this aspect, the device's emissive layer further comprises a host.

In another aspect the invention provides, the invention provides a method of synthesizing a compound of general formula (10), comprising combining in an appropriate solvent to form a reaction mixture (i) a cyclometalating ligand comprising two rings joined by one bond, the first ring being an aromatic or non-aromatic heterocycle that comprises at least one ring heteroatom, and the second ring being an aromatic carbocycle, wherein the first and second rings may be substituted or unsubstituted; and (ii) a charge-neutral platinum(ll) compound, wherein at least one Pt(ll) is bonded to four monodentate ligands, optionally, allowing reaction to proceed for an appropriate reaction time, adding to the reaction mixture strong acid, optionally, allowing reaction to proceed for an appropriate reaction time, adding to the reaction mixture a stabilizing ligand comprising a bidentate heteroaryl ligand comprising at least two heteroatoms, each heteroatom being available for bonding to the Pt(ll), wherein the bidentate heteroaryl ligand may be substituted or unsubstituted; and obtaining a product that is a Pt(ll) chelated by two different bidentate ligands wherein the first bidentate ligand is derived from the cyclometalating ligand and the second bidentate ligand is derived from the stabilizing Iigand, wherein substituents may be further substituted and comprise a non-aromatic carbocycle or heterocycle, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, BR ₂ , B(aryl) ₂ , aryl-B(aryl) ₂ , O, NR' ₂ , OR', a nitrile group, C(halo) ₃ which includes CF ₃ , or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof.

In an embodiment of this aspect, the amount of cyclometalating Iigand and strong acid are equimolar to the amount of Pt(ll), and the amount of bidentate Iigand is twice as much as the amount of Pt(ll). Another embodiment further comprising purifying the product. In some embodiments, the strong acid is: HBF ₄ , p-toluenesulfonic acid (TsOH), trifluoroacetic acid (TFA), picolinic acid (PA), or trifluoromethanesulfonic acid (TfOH). In some

embodiments, the stabilizing Iigand is 3-diketonato, 1 ,3-diketiminato, picolinato, or . In some embodiments, substituents comprise aliphatic, aryl, B(aryl) ₂ , B(aliphatic)(aryl), B(aliphatic)(aliphatic). In certain embodiments, the substituent comprises phenyl, isopropyl, n-butyl, t-butyl, or phenyl-BMes ₂ . In certain embodiments, the stabilizing Iigand is added as a solution formed by dissolving a salt form of the stabilizing Iigand that comprises a sodium, lithium or potassium counterion. In certain embodiments, the reaction mixture is maintained at ambient temperature and/or pressure. In certain

embodiments, the reaction mixture is maintained at about 55°C. In certain embodiments, the product is 1a, 1 b, 1c, 2a, 2b, 2c, 3, 4, 5, 6, 7, 8a, 8b, 8c, 9a, 9b, 9c, 21 , 22, 23, 24, or 25. In certain embodiments, the stabilizing Iigand is the conjugate base of the strong acid. In certain embodiments, the strong acid is picolinic acid. Certain embodiments further comprise adding heat. In certain embodiments, one or more steps are performed under an inert atmosphere. In certain such embodiments, the product is 11. Certain embodiments also comprise cooling. In certain embodiments, the product is BC1 , BC2,

Pt(B-NHC1 )(nacnac), or Pt(B-NHC2)(nacnac).

An aspect of the invention provides a method of synthesizing a Pt(ll) compound chelated by two different bidentate ligands comprising combining in an appropriate solvent to form a reaction mixture (i) a cyclometalating Iigand comprising two rings joined by one bond, the first ring being an aromatic or non-aromatic heterocycle that comprises at least one ring heteroatom, and the second ring being an aromatic carbocycle, wherein the first and second rings may be substituted or unsubstituted, (ii) a charge-neutral platinum(ll) compound, wherein at least one Pt(ll) is bonded to four monodentate ligands, optionally, allowing reaction to proceed for an appropriate reaction time, adding to the reaction mixture strong acid, optionally, allowing reaction to proceed for an appropriate reaction time, adding to the reaction mixture a stabilizing ligand comprising a bidentate heteroaryl ligand comprising at least two heteroatoms, each heteroatom being available for bonding to the Pt(ll), wherein the bidentate heteroaryl ligand may be substituted or unsubstituted; and obtaining a product that is a Pt(ll) chelated by two different bidentate ligands wherein the first bidentate ligand is derived from the cyclometalating ligand and the second bidentate ligand is derived from the stabilizing ligand, wherein substituents may be further substituted and comprise a

non-aromatic carbocycle or heterocycle, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, BR' ₂ , BR'(aryl), B(aryl) ₂ , aryl-B(aryl) ₂ , O, NR' _2l OR', a nitrile group, C(halo) ₃ which is optionally CF _3l or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof. In an embodiment of this aspect, at least one of the four monodentate ligands is a bridging ligand. In an embodiment of this aspect, the bridging monodentate ligand comprises at least one sulfur atom.

In an embodiment of this aspect, the charge-neutral platinum(ll) compound is

[PtR ^a ₂ (SR ^b ₂ )] _n , or PtR ^a ₂ (D SO) ₂ , wherein R ^a and R ^b are independently aliphatic or aryl, and n is 2 or 3. In an embodiment of this aspect, the [PtR ^a ₂ (SR ^b ₂ )] _n is [Pt(phenyl) ₂ (SMe ₂ )] ₂ or [PtMe ₂ (SMe ₂ )] ₂ . In another embodiment of this aspect, the PtR ^a ₂ (D SO) ₂ is Pt e ₂ (DMSO) ₂ or Pt(phenyl) ₂ (D SO) ₂ .

In an embodiment of this aspect, the amount of cyclometalating ligand and strong acid are equimolar to the amount of Pt, and the amount of bidentate ligand is twice as much as the amount of Pt. In an embodiment of this aspect, the aspect further comprises purifying the product. In an embodiment of this aspect, the strong acid is: HBF ₄ , p-toluenesulfonic acid, trifluoroacetic acid, picolinic acid, or trifluoromethanesulfonic acid.

In an embodiment of this aspect, the stabilizing ligand is j8-diketonato, 1 ,3-diketimino, picolinato, or

In another embodiment of this aspect, substituents comprise aliphatic, aryl, B(aryl) ₂ ,

B(aliphatic)(aryl), B(aliphatic)(aliphatic). In an embodiment of this aspect, the substituent is phenyl, isopropyl, n-butyl, t-butyl, or phenyl-BMes ₂ . In an embodiment of this aspect, the stabilizing Iigand is added as a solution formed by dissolving a salt form of the stabilizing Iigand that comprises a sodium, lithium or potassium counterion. In yet another embodiment of the above aspect, wherein the reaction mixture is maintained at ambient temperature and/or pressure. In an embodiment of this aspect, the reaction mixture is maintained at about 55°C. In an embodiment of this aspect, the product is 1a, 1 b, 1c, 2a, 2b, 2c, 3, 4, 5, 6, 7, 8a, 8b, 8c, 9a, 9b, 9c, 21 , 22, 23, 24, or 25.

In an embodiment of this aspect, the stabilizing Iigand is the conjugate base of the strong acid. In an embodiment of this aspect.the strong acid is picolinic acid. In an embodiment of this aspect, further comprising adding heat. In an embodiment of this aspect, one or more steps are performed under an inert atmosphere.

Certain embodiments further comprise adding heat. In some embodiments, one or more steps are performed under an inert atmosphere. Certain embodiments further comprise cooling. In certain embodiments, the product is 11 , BC1 , BC2,

Pt(B-NHC1 )(nacnac), or Pt(B-NHC2)(nacnac).

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example to the

accompanying drawings, which illustrate aspects and features according to preferred embodiments of the present invention, and in which:

Fig. 1 shows a preferred embodiment of a three layer electroluminescent (EL) display device according to the invention;

Fig. 2 shows a plot of the emission spectra of PMMA film doped with 5%

Pt-(F2Ph-Bn)(t-Bu-trz) (solid square) or 10% Pt-(F2Ph-Bn)(t-Bu-trz) (O);

Fig. 3 shows a plot of the emission spectra of PMMA film doped with 5%

Pt-(F2Ph-Bn)(CF3-trz) (solid square) or 10% Pt-(F2Ph-Bn)(CF3-trz) (O);

Fig. 4 shows a plot of the emission spectra of PMMA film doped with 5%

Pt-(Ph2NPh-Bn)(t-Bu-trz) (solid square) or 10% Pt-(Ph2NPh-Bn)(t-Bu-trz) (O);

Fig. 5 shows a plot of the emission spectra of PMMA film doped with 5%

Pt-(Ph2NPh-Bn)(CF3-trz) (solid square) or 10% Pt-(Ph2NPh-Bn)(CF3-trz) (O);

Fig. 6 shows a plot of the emission spectra of PMMA film doped with 5%

Pt-(Ph-Bn)(t-Bu-trz) (solid square) or 10% Pt-(Ph-Bn)(t-Bu-trz) (O);

Fig. 7 shows a plot of the emission spectra of PMMA film doped with 5%

Pt-(Ph-Bn)(CF3-trz) (solid square) or 10% Pt-(Ph-Bn)(CF3-trz) (O); Fig. 8 shows a plot of the emission spectra of PMMA film doped with 5% Pt-(Ph-Me)(t-Bu-trz) (solid square) or 10% Pt-(Ph-Me)(t-Bu-trz) (O);

Fig. 9 shows a plot of the emission spectra of PMMA film doped with 5%

Pt-(MePh-Bn)(CF3-trz) (solid square);

Fig. 10 shows a plot of the emission spectra of PMMA film doped with 10%

Pt-(Ph3CPh-CHPh2)(CF3-trz) (O) and 5% Pt-(Ph3CPh-CHPh2)(CF3-trz) (solid square);

Fig. 11 shows a plot of the emission spectra of PMMA film doped with 10%

Pt-(Ph3CPh-Bn)(CF3-trz) (O) and 5% Pt-(Ph3CPh-Bn)(CF3-trz) (solid square);

Fig. 12 shows an X-ray crystallographic structure of Pt-(Ph2NPh-Bn)(t-Bu-trz)("T1") with only certain atoms labelled for greater clarity;

Fig. 13 shows an X-ray crystallographic structure of Pt-(F2Ph-Bn)(CF ₃ -trz)("T8") with only certain atoms labelled for greater clarity;

Fig. 14 shows an X-ray crystallographic structure of Pt-(Ph2NPh-Bn)(t-Bu-trz)("T1") with full atom labelling;

Fig. 15 shows an X-ray crystallographic structure of Pt-(F2NPh-Bn)(CF3-trz) ("T8") with full atom labelling;

Fig. 16 shows an X-ray crystallographic structure of Pt-(Ph3CPh-Bn)(CF3-trz) ("T18"); Fig. 17 shows an X-ray crystallographic structure of Pt-(Ph3CPh-Ph2CH)(t-Bu-trz)

("T14");

Fig. 18 shows an X-ray crystallographic structure of Pt-(Ph3CPh-Ph2CH)(CF3-trz)

("T15");

Fig. 19 shows a plot of the emission spectra of PMMA film doped with 10%

Pt-(Ph3CPh-CHPH2)(t-Bu-trz) ("T10") (O) and 5% Pt-(Ph3CPh-CHPh2)(t-Bu-trz) ("T10") (solid square);

Fig. 20 shows the absorption (dashed) and emission (solid) spectra of BC1 and BC2 in methylene chloride at a concentration of 1.0 x 10-5 M;

Fig. 21 graphically shows current efficiencies for OLEDs based on BC1 and BC2;

Fig. 22 graphically shows power efficiencies for OLEDs based on BC1 and BC2;

Fig. 23 graphically shows cyclic voltammetry diagrams of BC1 and BC2 recorded in DMF with NBu ₄ PF ₆ as the electrolyte, scan rate 200 mV/s;

Fig. 24 shows the emission spectra of C1 (Δ); C2 (■); and C3 (O) in PMMA (10 wt%);

Fig. 25 shows the emission spectra of C4 (Δ); C5 (O); and C8 (■) in PMMA (10 wt%);

Fig. 26 shows the emission spectra of C6 (O); C6 (5%) (Δ); and C9 (■) in PMMA (10 wt% and 5 wt%, respectively); Fig. 27 shows the emission spectra of C10 (O); and C1 1 (5%) (■) in PMMA (10 wt% and 5 wt%, respectively);

Fig. 28 shows the emission spectra of C27 (5%) (■); and C27(0) in PMMA (10 wt% and 5 wt%, respectively);

Fig. 29 shows emission spectra of compound C12 in 1 wt%, 5 wt% and 10 wt% doped

PMMA films, respectively, after drying for 1 day;

Fig. 30 shows the absorption spectrum of Pt-12 in dichloromethane (concentration= 2.0 x 10 ^"5 M) at room temperature;

Fig. 31 shows the emission spectrum of Pt-12 in dichloromethane (c = 2.0x10 ^"5 M) at r.t. under nitrogen;

Fig. 32 shows the electroluminescent spectra of compound C6 doped at 5% in TcTa (tris(4-carbazoyl-9-ylphenyl)amine) host layer; and

Fig. 33 shows a plot of EQE versus luminance for compound C6.

Fig. 34 shows a crystal structure schematic for the molecular structure of BC1 with 50% thermal ellipsoids and labeling;

Fig. 35 shows a crystal structure schematic for the molecular structure of BC2 with 50% thermal ellipsoids and labeling;

Fig. 36 shows a crystal structure schematic for the molecular structure of C12;

Fig. 37 shows a crystal structure schematic for the molecular structure of Pt-9;

Fig. 38 shows a crystal structure schematic for the molecular structure of Pt-1 10;

Fig. 39 shows an plot of Intensity vs. Wavelength (EL spectra) of EL devices using Pt-9 or Pt-1 10 as dopant;

Fig. 40 shows an Luminance-Current Density-Voltage (L-J-V) plot of EL devices using Pt-9 or Pt-1 10 as dopant;

Fig. 41 shows an L-J-V plot of EL devices using Pt-9 or Pt-1 10 as dopant;

Fig. 42 shows an EQE-L plot of EL devices using Pt-9 or Pt-1 10 as dopant;

Fig. 43 shows a phosphorescence spectra of ^-trans (A) and N ^A -trans (B) isomers of Pt-8 in 5 wt% and 10 wt% PMMA films; and

Fig. 44 shows EL devices structure as well as materials used. DETAILED DESCRIPTION OF THE INVENTION

Definitions

As used herein, the term "TfOH" means trifluoromethanesulfonic acid, which is also known as triflic acid or CF ₃ SO ₃ H. The term "TsOH" means p-toluenesulfonic acid. The term "TFA" means trifluoroacetic acid. The term "PA" means picolinic acid.

As used herein, the terms "N ^A C" chelate, "Ν ^Λ Ν" chelate, "P ^A C" chelate, and "C ^A C" chelate are used to indicate what atoms are bonded to the metal. That is, "N ^A C" indicates that a nitrogen and a carbon are bonded to the metal, "N ^A N" indicates that two nitrogens are bonded to the metal, "P ^A C" indicates that a phosphorus and a carbon are bonded to the metal, and "C ^A C" indicates that two carbons are bonded to the metal.

As used herein, the term "chelation" indicates formation or presence of bonds (or other attractive interactions), e.g., coordination bonds, between a single central atom and two or more separate binding sites within the same ligand.

As used herein, the term "cyclometalation" refers to a reaction of transition metal complexes in which an organic ligand undergoes intramolecular metalation with formation of a metal-carbon sigma bond (Bruce, Michael I., Angewandte Chemie Int'l Ed. (2003) 16(2): 73-86).

As used herein "EQE" refers to external quantum efficiency.

As used herein "aliphatic" includes alkyl, alkenyl and alkynyl. An aliphatic group may be substituted or unsubstituted. It may be straight chain, branched chain or cyclic.

As used herein "aryl" includes aromatic carbocycles and aromatic heterocycles and may be substituted or unsubstituted.

As used herein, B means boron.

As used herein the term "Mes" means mesityl, which is also known as

2,4,6-trimethylphenyl.

As used herein the term "acac" refers to β-diketonato. As used herein the term "nacnac" refers to β-diketimino. As used herein the term picolinato may appear abbreviated as "pico".

As used herein, the term "PMMA" refers to polymethylmethacrylate, a polymer.

As used herein, the term "unsubstituted" refers to any open valence of an atom being occupied by hydrogen. Also, if an occupant of an open valence position on an atom is not specified then it is hydrogen.

As used herein "substituted" refers to the structure having one or more substituents. As used herein "heteroatom" means a non-carbon, non-hydrogen atom. In some cases, a heteroatom may have a lone pair of electrons available to form dative or coordinate bonds (e.g., N, O, P).

As used herein, the term "dative bond" refers to a coordination bond formed when one molecular species serves as a donor and the other as an acceptor of an electron pair to be shared in formation of a complex.

As used herein, the term "monodentate ligand" refers to a moiety that has a single site that is suitable for binding a metal ion. In general, the stability of a metal complex correlates with the denticity of its ligands, where denticity is defined as, "in a coordination entity the number of donor groups from a given ligand attached to the same central atom" (lUPAC Gold Book). This is thought to be because monodentate ligands are more apt to dissociate from a metal ion than a bidentate or multidentate ligand. This phenomenon is considered to be due to the proximity of the ligand to the metal ion. For example, in solution, when a monodentate ligand dissociates from a metal ion, it drifts away from the metal ion. In contrast, when a bidentate ligand dissociates at one of its two binding sites, the other binding site's bond means that the bidentate ligand remains in the proximity of the metal ion. For this reason, it is likely to reform a bond between the available binding site and the metal ion. Thus a bidentate metal complex is more stable than a monodentate metal complex. Embodiments

Compared with Ir(lll) complexes, Pt(ll) compounds that have a high phosphorescent quantum efficiency are scarce. This scarcity is due to strong intermolecular π-π stacking interactions caused by Pt(ll) complexes' square planar geometry and the structural distortion in the excited state. Such interactions and distortion lead to excimer formation and decreases in emission quantum efficiency and color purity in the solid state. The square planar geometry of Pt(ll) may have one advantage over Ir(lll), namely the access to a higher triplet state. Such access is due to greater ligand field splitting for a given set of chelate ligands, which greatly increases the energy of the d-d state. Thus, Pt(ll) compounds are good candidates for development of bright phosphorescent emitters with colors ranging from blue to red, if low emission efficiency and intermolecular interaction issues can be addressed. Several examples of green, orange or red phosphorescent Pt(ll) compounds have been demonstrated recently for successful use in PhOLEDs (A. F. Rausch et a/., Proc. SPIE 2007, 6655, 66550F/1 ; B. Ma et a/., Adv. Fund. Mater. 2006, 16, 2438; V. Adamovich et a/., New J. Chem. 2002, 26, 1 171 ; B. W. D'Andrade et al.,Adv. Mater. 2002, 14, 1032; J. A. G. Williams et al., Coord. Chem. Rev. 2008, 252, 2596; W. -Y. Wong et al., Organometallics, 2005, 24, 4079; G. Zhou et al., J. Mater. Chem., 2010, 20, 7472; J. Kavitha et al., Adv. Fund. Mater., 2005, 15, 223; S.-Y. Chang et al., Inorg. Chem., 2007, 46, 7064; S.-Y. Chang et al., Dalton Trans., 2008, 6901 ; Z, . Hudson et al., Adv. Fund. Mater. 2010, 20, 3426; Z. M. Hudson ef al., Dalton Trans., 2011 , 40, 7805; Z. Wang ef al., Appl. Phys. Lett., 2011, 98, 213301 ; Z. M. Hudson et al., Chem. Commun., 2011 , 47, 755).

Blue PhOLEDs based on Pt(ll) compounds are very rare and only a few examples are known in the literature (K. Li, X. Guan et al., Chem. Commun., 2011 , 47, 9075; Y. Unger, ei al., Angew. Chem. Int. Ed., 2010, 49, 10214; E. L. Williams et al., Adv. Mater.2007, 19 ,197; M. Cocchi, ei al., Appl. Phys. Lett. 2009, 94, 073309; . Cocchi, ef al., Adv. Fund. Mater., 2007, 17, 285; X. Yang et al., Adv. Mater. 2008 , 20 , 2405; S.-Y. Chang et al., Inorg. Chem. 2007, 46, 1 1202).

The term "cyclometalation" refers to a reaction of a transition metal complex in which an organic ligand undergoes intramolecular metalation with formation of a metal-carbon sigma bond (Bruce, Michael I., Angewandte Chemie Int'l Ed. (2003) 16(2): 73-86).

Cyclometalating ligands are described and characterized herein and were used to prepare platinum (II) complexes. For clarity, the below schematic shows an example

cyclometalating ligand and an example Pt complex. The cyclometalating ligand has two rings bonded together through one bond so that when this ligand chelates a metal ion, the metal atom becomes part of a newly-formed five- or six-membered ring (see below). In certain embodiments, these Pt(ll) complexes are luminescent (i.e., phosphorescent).

Cyclometalating ligand

Newly formed

The inventors of this discovery have found that cyclometallated Pt complexes of general formula (10), as described below, have promising PhOLED properties such as high photoluminescent quantum efficiencies and may offer one or more of the key color components for electroluminescent devices. Details regarding synthesis and characterization of such compounds are provided herein. Compounds having general formula (10) are:

cyclometallating

ligand

stabilizing

ligand

(10)

wherein a dotted line in a ring indicates that the ring can be saturated, unsaturated, aromatic, or non-aromatic, Y is independently N or O, X is independently C or N and at least

f Q h

one X is N, w is independently 0 to 5, t is 0 or 1 , R , R , and R are independently a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, C(R') ₂ , CR'(aryl), C(aryl) ₂ , B(R') ₂ , BR'(aryl), B(aryl) ₂ , aryl-B(aryl) ₂ , O, NR' ₂ , NR'(aryl), N(aryl) ₂ , OR', a nitrile group, C(halo) ₃ which is optionally CF ₃ , or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof, substituents are an aliphatic moiety, an aryl moiety, amine, halo, thioether, ether, or any combination thereof; and wherein a substituent can be further substituted; and optionally R ^f is B(substituted- or unsubstituted-aryl) ₂ with the proviso that B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond and with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C ₃ , branched C ₄ , or linear or branched C ₅ -or higher.

Acceptable substituents include any chemical moiety that does not interfere with the desired reaction and may include, for example: a non-aromatic carbocycle or heterocycle, an aryl group (which includes a heteroaryl) that is attached as a fused ring or as a substituent, a hydroxy group, nitro, amino, halo, BR ₂ , B(aryl) ₂ , aryl-B(aryl) ₂ , O, NR ₂ , OR, a nitrile group,

-C(halo) ₃ which includes -CF ₃ , and R, where R is a substituted or unsubstituted aliphatic group having 1-24 carbon atoms which may be straight, branched or cyclic (e.g., adamantyl). A substituent may be further substituted.

An embodiment of the compound of general formula (10) is also a compound of eneral formula (1 ):

(1)

wherein R ^a is H, a substituted or unsubstituted aliphatic moiety (e.g., t-butyl, CF ₃ ), halo, a substituted or unsubstituted aryl moiety (e.g., phenyl, benzyl), or any combination thereof, R is a substituted or unsubstituted aliphatic moiety (e.g., methyl, adamantyl), or a substituted or unsubstituted aryl moiety (e.g., benzyl, diphenylmethyl) or any combination thereof (e.g., Me, benzyl), R ^c is H, or a substituted or unsubstituted aliphatic moiety, substituted or unsubstituted aryl moiety (e.g., Me) or any combination thereof, R ^d is H, or a substituted or unsubstituted aliphatic moiety (e.g., methyl, adamantyl), a substituted or unsubstituted aryl moiety (e.g., phenyl, benzyl), or a substituted or unsubstituted amine, halo, thioether, ether, or any combination thereof, n is a number from 0 to 4, and substituents are an aliphatic moiety, an aryl moiety, amine, halo, thioether, ether, or any combination thereof.

Another embodiment of general formula (10) is also a compound of general formula

(100):

(100) wherein B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond, R is a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, B(R') _2> BR'(aryl), B(aryl) ₂ , aryl-B(aryl) ₂ , O, NR' ₂ , OR', a nitrile group, C(halo) ₃ which is optionally CF ₃ , or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof, k, p and h are independently 0 to 5, m and j are independently 0 to 3, and k, h and m are not all 0, with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C ₃ , branched C ₄ , or linear or branched Cs-or higher, t is 0 or 1 , a dotted line in a ring indicates that the ring can be saturated, unsaturated, aromatic, or non-aromatic, X is independently C or N and at least two X are N; and Y is independently N or O, wherein a substituent can be further substituted. In some embodiments, one of the two X that is N is bonded to Pt.

Compounds of general formula (100) include cyclometalated Pt(ll) 3-diketonate,

cyclometalated Pt(ll) /3-diketiminate, and cyclometalated Pt(ll) picolinate complexes.

In some embodiments, in regard to moieties on ring 6 of general formula (1 ), there is a methyl group located para to the pyridyl ring nitrogen, which position is known herein as "para-to-pyridyIN". In certain embodiments, R ^a is H, and on ring 6, R ^d located para-to-pyridyIN is CH ₃ .

In some embodiments of compounds of general formula (1 ), it is desirable to have at least one of R ^a"d be a sterically bulky moiety to prevent π-π stacking, excimer formation and/or dimer formation. Sterically bulky moieties include t-butyl, iso-propyl, diarylamine, or triarylmethyl. Accordingly, in certain embodiments described herein, on ring 1 in the para position to the 1 ,2,3-triazole ring (this position is denoted in general formula (1 ) above), R ^d is diphenylamine or triphenylmethyl. In other embodiments, on ring 2, R ^b is diphenylmethyl or benzyl. In some embodiments, on ring 4, R ^a is CF ₃ or t-Bu.

When the substituted cyclometalating ligand is used to form a compound of general formula (10), a highly efficient phosphorescent Pt(ll) compound can be achieved. In some embodiments, the phosphorescence is blue.

The effect of the presence of substituents (i.e., R ^a'd and substituents thereof) plays an important role in the high performance of the resulting Pt(ll) compounds of general formula (10) in PhOLEDs. It facilitates the mixing of the ³ LC and the LCT state, thus enhancing the intrinsic phosphorescent efficiency of the molecule. It minimizes intermolecular interactions, thus enhancing emission efficiency in the solid state. Also, it also enhances the rigidity of the molecule, thus minimizing the loss of phosphorescence via non-radiative pathways. In certain embodiments of the invention, a compound of general formula (10) exhibits intense luminescence, which may be photoluminescence and/or electroluminescence.

Compounds of general formula (10) comprise a substituted or unsubstituted phenyl ring (indicated as ring 1 ) that is bonded to the Pt through one of its carbon ring atoms. In some embodiments, ring 1 is unsubstituted. In certain embodiments, ring 1 is substituted by one, two, three of four R ^d moieties, where R ^d is independently H, a substituted or

unsubstituted aliphatic moiety, a substituted or unsubstituted aryl moiety, a substituted or unsubstituted amine, halo, thioether, ether, or any combination thereof. In certain

embodiments, Rd is an aryl substituted amine. In some embodiments R ^d is triphenylmethyl.

Ring 2 in general formula (1 ) is a 1 ,2,3-triazolyl moiety. That is, it is an aromatic 5-membered heterocycle that has three ring nitrogens located all in a row. Ring 2 is substituted at least at the position indicated in general formula (1 ) with R ^b . Ring 2 is optionally further substituted at the position indicated with R ^c . Notably, R ^b is a substituted or unsubstituted aliphatic moiety (e.g., methyl, adamantyl), or a substituted or unsubstituted aryl moiety (e.g., benzyl), while R ^c is hydrogen, or a substituted or unsubstituted aliphatic moiety, substituted or unsubstituted aryl moiety (e.g., Me). Suitable substituents include any moiety that does not interfere with the luminescence of such compounds. Optionally, ring 2 may be part of a fused ring system that may be further substituted.

The cyclometalating ligand formed by rings 1 and 2 of general formula (10) is a bidentate ligand, and as such, two atoms form bonds with the Pt(ll). The first metal-bonding atom is a carbon ring atom of the ring 1 , and the second is a nitrogen ring atom of the ring 2. This bidentate ligand is referred to herein as a phenyl-triazolyl ligand. Ring 3 of the compounds of general formula (10) is formed by a cyclometalation reaction as described above.

Compounds of general formula (1 ) further comprise a second five-membered heteroaromatic ring (the first being ring 2), which is designated as ring 4 in general formula (1 ). Ring 4 is a 1 ,2,4-triazolyl moiety. That is, it has three nitrogen ring atoms that, in contrast to ring 2, are not all in a row, but rather are separated by a ring carbon. Ring 4 can be substituted as shown by moiety R ^a in general formula (1 ). Suitable substituents for ring 4 include any moiety that does not interfere with the luminescence of such compounds.

Accordingly, R ^a is H, a substituted or unsubstituted aliphatic moiety (e.g., t-butyl or CF ₃₎ , or a substituted or unsubstituted aryl moiety (e.g., benzyl). Optionally, ring 4 may be part of a fused ring system. The rings of the fused ring system may be substituted.

Compounds of general formula (1 ) further comprise a pyridyl moiety (ring 6). Ring 6 can be mono-substituted or multi-substituted provided that there is no substituent at either carbon that is located ortho to the pyridyl nitrogen (the ortho carbon that has an open valence position is bonded to a hydrogen). Suitable substituents for ring 6 include any moiety that does not interfere with the luminescence of such compounds. Accordingly, R ^d is

independently H, a substituted or unsubstituted aliphatic moiety, a substituted or

unsubstituted aryl moiety, a substituted or unsubstituted amine, halo, thioether, ether, or any combination thereof.

The ligand formed by rings 4 and 6 of general formula (1 ) is a bidentate ligand, and as such, two atoms form bonds with the Pt(ll). The first metal-bonding atom is a nitrogen ring atom of the ring 4, and the second is a nitrogen ring atom of the ring 6. This bidentate ligand is referred to herein as a stabilizing ligand because it saturates the coordination sphere of the Pt(ll) center and provides a rigidity to the molecule, which discourages ligands from dissociating from the Pt(ll).

Prior to this discovery, cyciometalated platinum /3-diketonates have typically been prepared by a modified method of Lewis and coworkers (Brooks, J. et al. Inorg. Chem. 2002, 41, 3055-3066; and Cockburn, B. N. et al. J. Chem. Soc, Dalton Trans. 1973, 404-410). This process is a two-step process in which 2 to 2.5 equivalents of cyclometalating ligand are heated with K ₂ PtCI ₄ to give a chloro-bridged platinum dimer, which is then heated with Na ₂ C0 ₃ and /?-diketone to give the final product.

20-40% overall yield

Scheme showing previously known preparation method for cyclometalated Pt(ll) j8-diketonates

This previously known process has several disadvantages. It requires long reaction times at high temperatures and provides typical yields of only 20-40% over two steps. Its requirement for excess ligand can be particularly problematic, as the organic ligands used for many applications in advanced materials are often of considerable value. Furthermore, high temperature reaction conditions limit the variety of cyclometalating ligands that can be used to prepare such complexes.

The present inventors have developed an efficient one-pot synthesis of

cyclometalated platinum complexes. In some embodiments of this one-pot synthesis, mild conditions are used for short reaction times, and high yields of product are obtained. In some embodiments, this improved reaction sequence can be conveniently carried out at ambient temperature under an atmosphere of air in less than 3 hours.

In embodiments of the invention, a one-pot, three step reaction provides a product that has Pt(ll) chelated by two different bidentate ligands. The first bidentate ligand is derived from the cyclometalating ligand (e.g, 2-phenylpyridine). The second bidentate ligand is derived from the stabilizing ligand (e.g., Pt(ppy)(acac). In the case of the specific example shown in the synthetic scheme below, the product was isolated as analytically pure material in 87% yield following column chromatography. Thus, a one-pot, two- or three-step reaction provides a product with general formula (1 ), which has Pt(ll) chelated by two different bidentate ligands wherein the first bidentate ligand is derived from a substituted or unsubstituted phenyl-triazolyl ligand and the second bidentate ligand is derived from a stabilizing ligand.

Synthetic scheme showing one-pot synthesis of a cyclometalated Pt(ll) 8-diketonates

Clean conversion to a cyclometalated diketonate complexes was observed for arenes substituted with both electron-rich (e.g., -OMe and -NR ₂ ) and electron deficient (-F, -CI) moieties. In both instances of substituent type, there was little variation in overall yields observed. This improved method was also successful in synthesis of heterocyclic

N ^A C-chelate complexes, and was used to synthesize benzofuran, benzothiazole, and

/V-phenylindole derivatives in 92, 89, and 83% yield, respectively. Incorporation of extended TT-systems was equally facile. Platinum -diketonate complexes of 2-phenylquinoline and benzo[ ?]quinoline (see Table 1 ) were readily prepared in yields of 87 and 76%. An improved synthesis of several triarylboron-functionalized platinum phosphors was also effected. Yields of these boryl-functionalized Pt(ll) compounds were about 4 to 5 times greater than those obtained using the PtCI(DMSO)(acac) precursor methods (Hudson, Z. M. et al. Adv. Fund. Mater. 2010, 20, 3426-3439, and Hudson, Z. M. et al. Chem. Commun. 201 1 , 47, 755-757).

The working examples provide detailed descriptions of syntheses of specific compounds of general formula (10), whose structural formulae are shown in Table 1. As would be apparent to a person of ordinary skill in the art, other structural variations may be used according to the invention. Starting materials may be modified to include moieties that confer desirable physical or chemical properties, such as increased stability or luminescence.

When introduced in the synthesis of certain compounds of general formula (10), the stabilizing ligand is a bidentate chelate ligand:

One ring of this bidentate chelate ligand has three nitrogen ring atoms wherein at least one nitrogen ring atom is available for bonding to the Pt(ll). Also, the pyridyl nitrogen is available for bonding to the Pt(ll). Exemplary stabilizing ligands include

2-(1 H-1 ,2,4-triazol-5-yl)pyridine. The stabilizing ligand can be unsubstituted,

mono-substituted, or multi-substituted. A substituent may form fused rings with the metal-bonding heteroatoms (e.g. pyridyl, triazole, pyrazole, imidazole, etc), Suitable substituents include any moiety that does not interfere with the phosphorescence of such compounds.

Notably, for compounds described herein (e.g., those having a Pt bound to a phenyl-triazolyl cyclometallating ligand and a 3-diketonate stabilizing ligand), the stabilizing ligand is not identical to the cyclometallating ligand. Without wishing to be bound by theory, the inventors contemplate that the non-identicalness of the stabilizing ligands and the cyclometallating ligand may be beneficial for improving quantum efficiency of these phosphorescent metal complexes.

Another starting material for this one-pot synthesis is a charge-neutral platinum(ll) compound, wherein a Pt(ll) is bonded to four monodentate ligands. By being

charge-neutral, this starting material is soluble in a variety of non-aqueous solvents (e.g., tetrahydrofuran (THF)). By having monodentate ligands occupying the four coordination sites of the Pt(ll), this starting material is a good source of Pt(ll) that is readily able to form bonds with a cyclometalating bidentate ligand. Thus, when treated with stoichiometric quantities of the cyclometalating ligand (e.g., 2-phenylpyridine ("ppy"),

phenyl-benzyl-1 ,2,3-triazole ("Ph-Bn-trz"))) in an appropriate solvent at ambient temperature, the charge-neutral platinum(ll) starting material reacts to provide a cyclometalated Pt(ll) complex with irreversible loss of a monodentate ligand. Specifically, the first reaction product, Pt( Ph-Bn-trz)Me(SMe ₂ ), is obtained through irreversible loss of a monodentate ligand (e.g., CH ₄ ).

An example of such a Pt starting material for the synthesis of compounds of general formula (1 ), is [PtMe ₂ (SMe ₂ )]2, which has been widely used as a precursor in C-H activation chemistry and can be easily prepared on a multi-gram scale from K ₂ PtCI ₄ (Scott, J. D.;

Puddephatt, R. J. Organometallics 1983, 2, 1643-1648). Other examples of suitable Pt starting materials include Pt(phenyl) ₂ (DMSO) ₂ (Klein, A. et al., Organometallics, 2005,17, 4125) and [Pt(phenyl) ₂ (SMe ₂ )] _n wherein n is 2 or 3 (Song, D.ef a/., J. Organomet. Chem. 2002, 648, 302-305).

Another starting material for the synthesis of such compounds is a strong acid. Such an acid is of sufficient strength to, for example, protonate an alkanyl moiety (e.g., -CH ₃ is protonated to CH ₄ ). An example of a strong acid is HBF ₄ . In some embodiments of the invention, the strong acid is a strong organic acid. Examples of strong organic acids include: p-toluenesulfonic acid (TsOH), trifluoroacetic acid (TFA), or picolinic acid (PA). For certain embodiments, trifluoromethane- sulfonic acid (TfOH) may be used; however, for other embodiments this choice of acid may lead to unwanted side reactions. In some embodiments, the strong acid acts in a dual role. In such embodiments, the acid not only protonates, but its conjugate base bonds to the metal and fulfils the role of acts a stabilizing ligand (discussed herein). Picolinic acid is one example of a dual role acid, and complexes with picolinate as the stabilizing ligand are described herein.

As shown in the second step of the above synthetic scheme, treatment of the Pt(ll) reaction mixture with one equivalent of a strong organic acid leads to rapid loss of one equivalent of monodentate ligand (e.g., CH ₄ ) providing the corresponding complex, which includes two labile ligands that can be readily replaced by a stabilizing ligand.

As shown in the third step of the above synthetic scheme, another starting material for the one-pot synthetic method is a stabilizing ligand, which is a negatively-charged bidentate ligand that is capable of forming a 5- or 6-membered ring having as its ring atoms, the Pt(ll) atom and at least two heteroatoms. Each of the at least two ring heteroatoms is available for bonding to the Pt(ll). The stabilizing ligand may be substituted or unsubstituted. The stabilizing ligand forms a 5- or 6-membered metallocycle with the Pt, which may be aromatic or non-aromatic, saturated or unsaturated, and may have fused rings bonded to the metallocycle. Exemplary stabilizing ligands include /3-diketonate ("acac"), -diketimino ("nacnac"), picolinate, and

While presence of substituents on the cyclometalating ligand of a Pt(ll) jS-diketonates is more common, considerable research has also been devoted to functionalization of Pt complexes on the stabilizing ligand. While acetylacetonate (acac) is by far the most widely used of these, diketimino (nacnac), dibenzoylmethane (dbm) and dipivaloylmethane (dpm) have also appeared in numerous studies, with notably different physical properties. Using these as representative examples in reaction with 2-phenylpyridine, this method is shown to be applicable using alternative 3-diketonate ligands with no significant reduction in overall yield (1 b, 1 c).

Synthesis and characterization of platinum -diketonate P ^A C-chelate complexes is also described herein. Specifically, the reaction of (l-naphthyl)diphenylphosphine with [PtMe ₂ (SMe ₂ )] ₂ was successfully carried out under a nitrogen atmosphere to prevent oxidation of the phosphine. This cyclometalation reaction was carried out under mild heating at 55 °C for 4h. Following reaction with acid and acetylacetonate at room temperature, the corresponding Pt(P ^A C)(acac) complex was successfully obtained in 65% yield.

The one-pot synthetic method described herein was also applied to prepare

C ^A C-chelate carbene complexes of platinum 3-diketonates and -diketiminates. Few examples of such products have appeared in literature, those that do required several days at high temperature to prepare (Haneder, S. ef a/., Adv. Mater. 2008, 20, 3325-3330 and Unger, Y. et al., Angew. Chem. Int. Ed. 2010, 49, 10214-10216). Literature methods required initial formation of a silver(l) carbene species, followed by transmetalation with Pt(COD)CI ₂ (COD = 1 ,4-cyclooctadiene) at 100 °C for 16h, followed by reaction with /3-diketone and Na(O-f-Bu) at 100 °C for a further 16 h. Using /V-methyl-/V'-phenylimidazolium iodide as a representative example, it was determined that the synthetic method described herein could be adapted to give C ^A C chelate carbene complexes of platinum /3-diketonates. These complexes remain most conveniently prepared via Ag(l) carbene starting materials, which can be isolated after reaction of imidazolium salt with Ag ₂ 0 at room temperature. This species was then stirred for 1 hr with [PtMe ₂ (SMe ₂ )] _2l and filtered to remove precipitated Agl. Mild heating was then required for cyclometalation of the pendant phenyl group, with complete reaction observed after 2 hrs at about 55 °C followed by reaction with acid at room temperature. Surprisingly, addition of Na(acac) as a neat solid or in methanol led to rapid decomposition, giving a complex mixture of products not isolable by column chromatography. This undesired reactivity in the final step was readily avoided by cooling the reaction mixture to -40°C, and after 2 hrs the corresponding Pt(C ^A C)(acac) complex was successfully isolated in about 61 % yield.

A series of new blue and blue-green phosphorescent Bptrz C ^A N chelate Pt(ll) compounds have been described herein. Three different classes of ancillary stabilizing ligands were examined and were found to have a distinct impact on the phosphorescent quantum efficiency. Pyridyl-1 ,2,4-triazole (pytrz) ligands were the most effective in enhancing the blue phosphorescent quantum efficiency of the Pt(ll) compounds. Although not wishing to be bound by theory, the inventors suggest that the double intramolecular hydrogen bonds formed between pytrz and Bptrz in the complex was found to enhance stability and emission efficiency of the Pt(ll) compounds. Substituent groups on the ancillary stabilizing ligands were found to influence the extent of excimer formation and quantum efficiency. Bright white phosphorescence as a result of the excimer and the monomer emission was observed from some of the Pt(Bptrz)(pytrz) compounds. Preliminary evaluation on the performance of two members of Pt(Bptrz)(pytrz) compounds demonstrated that they are promising candidates in producing highly efficient blue or white phosphorescent OLEDs using a single dopant.

In another aspect, in place of cyclometalating ligand described above, a different ligand was used, which ligand comprises an aromatic carbocycle that was part of a fused ring system, which fused ring system was substituted by a heteroatom, and wherein the ligand may be further substituted. This ligand formed bonds with the Pt(ll) at a carbon of the carbocycle, and at the heteroatom. Synthetic details are provided in the Working Examples for such a compound, see compound 10.

As discussed above, a one-pot method for the preparation of cyclometalated platinum complexes is described herein and various products of this method were prepared and fully characterized (see Working Examples). This new synthetic method provides such compounds at significantly higher yield and lower cost than traditional methods.

Advantageously, this method merely requires stoichiometric equivalents of cyclometalating ligand relative to Pt, with typical yields of 80-90% after 3 hours reaction time at ambient temperature. As shown herein, this method was found to be versatile toward a broad array of functional groups and heterocyclic systems, and was adapted to prepare N ^A C-, P ^A C- and C ^A C-chelated platinum complexes

Data regarding luminescence of compounds of general formula (10) is shown in the

Tables. Such compounds of general formula (10) are photoluminescent or

electroluminescent. Thus, embodiments of the invention provide compounds that are photoluminescent and, in at least some embodiments of the invention, electroluminescent; they may produce intense light.

In embodiments of the invention, a composition is provided which comprises a photoluminescent or electroluminescent compound of general formula (10), an organic polymer, and a solvent. In other embodiments of the invention, a composition is provided which comprises a photoluminescent or electroluminescent compound of general formula (10), an organic polymer, and a solvent.

The invention also provides a method of producing photoluminescence comprising the steps of: providing a photoluminescent compound of the invention having general formula (10) which include compounds of general formula (1 ) and (100); and irradiating said photoluminescent compound with radiation of a wavelength suitable for exciting the compound to photoluminesce. The invention further provides a method of producing electroluminescence comprising the steps of: providing an electroluminescent compound of the invention having general formula (10); and applying a voltage across said electroluminescent compound.

The invention further provides an electroluminescent device for use with an applied voltage, comprising: a first electrode, an emitter (e.g., phosphor) which is an

electroluminescent compound of the invention optionally doped in a host material, and a second, transparent electrode, wherein a voltage is applied between the two electrodes to produce an electric field across the emitter.

The invention further provides an electroluminescent device for use with an applied voltage, comprising: a first electrode, an electron transport layer, an emitter (e.g., phosphor) which is an electroluminescent compound of the invention doped in a host material, a hole transport material, and a second, transparent electrode. When a voltage is applied between the two electrodes, it produces an electric field across the emitter and the emitter

consequently electroluminesces. In some embodiments of the invention, the device includes one or more charge transport layers interposed between the emitter and one or both of the electrodes. For example, spacing of an embodiment of the device, called for the purposes of the present specification, a "three layer EL device", is: first electrode, first charge transport layer, emitter in a host layer, second charge transport layer, and second transparent electrode.

An advantage of certain embodiments of the invention is that they compounds that are soluble in common solvents such as toluene, diethyl ether, tetrahydrofuran (THF), and dichloromethane. This permits the compounds to be blended easily and conveniently with polymers. The role of the polymer in such a mixture is at least two-fold. First, a polymer can provide protection for the compound from air degradation. Second, a polymer host matrix permits use of a solution-based process (e.g., ink-jet printing), a spin-coating process, or a dip-coating process as an alternative way to make films. Although spin-coating and dip-coating processes may not produce as high quality films as those produced by chemical vapor deposition (e.g., ink-jet printing) or vacuum deposition, they are often much faster and more economical.

Accordingly, the invention further provides methods of applying compounds as described above to a surface. These methods include solvent cast from solution, electrochemical deposition, vacuum vapor deposition, chemical vapor deposition, spin coating and dip coating. The compounds may be applied alone or with a carrier. In some embodiments of the invention, they are applied in a composition including an organic polymer. Such compositions are also encompassed by the invention. As an example of this application, compounds of general formula 100 form a clear transparent solution with the weakly-luminescent polymer PMMA. This can be converted to a transparent film by evaporating the toluene solvent via either a dip-coating or spin-coating process. Films obtained in this way are stable. Certain polymers such as, for example, PVK, are expected to further enhance the luminescence of an emitter in the film. Conveniently, spin coating may be performed using a Chemat Technology spin-coater KW-4A; and vacuum deposition may be performed using a modified Edwards manual diffusion pump.

Certain compounds of the invention have high chemical and/or thermal stability. As a result, they are suitable for vacuum deposition methods used in fabricating single- or multi-layer OLED devices.

The invention provides a method of producing electroluminescence comprising the steps of: providing an electroluminescent compound of the invention having general formula (10); and applying a voltage across said electroluminescent compound so that the compound electroluminesces.

According to the invention, electroluminescent devices for use with an applied voltage are provided. In general, such a device has a first electrode, an emitter which is an electroluminescent compound of the invention, and a second, transparent electrode, wherein a voltage is applied between the two electrodes to produce an electric field across the emitter of sufficient strength to cause the emitter to electroluminesce. Preferably, the first electrode is of a metal, such as, for example, aluminum, which reflects light emitted by the compound; whereas the second, transparent electrode permits passage of emitted light therethrough. The transparent electrode is preferably of indium tin oxide (ITO) glass, flexible polymer, or an equivalent known in the art. Here, the first electrode is the cathode and the second electrode is the anode.

In some embodiments of the invention, an EL device includes one or more charge transport layers interposed between the emitter and one or both of the electrodes. Such charge transport layer(s) are employed in prior art systems with inorganic salt emitters to reduce the voltage drop across the emitter. In a first example of such a device, layers are arranged in a sandwich in the following order: first electrode, charge transport layer, emitter and host, second charge transport layer, and second transparent electrode. In an embodiment of this type, a substrate of glass, quartz or the like is employed. A reflective metal layer (corresponding to the first electrode) is deposited on one side of the substrate, and an insulating charge transport layer is deposited on the other side. The emitter layer which is a compound of the invention is deposited on the charge transport layer, preferably by vacuum vapor deposition, though other methods may be equally effective. A transparent conducting electrode (e.g., ITO) is then deposited on the emitter layer. An effective voltage is applied to produce electroluminescence of the emitter.

In a second example of an EL device of the invention, a second charge transport layer is employed, and the sandwich layers are arranged in the following order: first electrode, first charge transport layer, emitter and host, second charge transport layer and second, transparent electrode.

Electroluminescent devices of the invention may include one or more of the emitting compounds described herein. In some embodiments of the invention, an

electroluminescent device such as a display device (e.g., flat panel display device, flexible display device, wearable display device) may include not only a blue- or green-emitting phosphor as described herein, but may be a multiple-color display device including one or more other phosphors. The other phosphors may emit in other light ranges, e.g., red, green, and/or be "stacked" relative to each other. Convenient materials, structures and uses of electroluminescent display devices are described in Rack, P.D.; Naman, A.; Holloway, P.H.; Sun, S.-S.; and Tuenge, R. T. Materials used in electroluminescent displays." MRS Bulletin (1996) 21 (3): 49-58.

For photoluminescence, the compounds absorb energy from ultraviolet radiation and emit visible light near the ultraviolet end of the visible spectrum, e.g., in the blue region. For electroluminescence, the absorbed energy is from an applied electric field.

The invention further provides methods employing compounds of the invention to harvest photons, and corresponding devices for such use. Spectroscopic studies have demonstrated that compounds of the invention have high efficiency to harvest photons and produce highly polarized electronic transitions. In general, when such compounds are excited by light, a charge separation occurs within the molecule; a first portion of the molecule has a negative charge and a second portion has a positive charge. Thus the first portion acts as an electron donor and the second portion as an electron acceptor. If recombination of the charge separation occurs, a photon is produced and luminescence is observed. In photovoltaic devices, recombination of the charge separation does not occur; instead the charges move toward an anode and a cathode to produce a potential difference, from which current can be produced.

Organic semiconducting materials can be used in the manufacture of photovoltaic cells that harvest light by photo-induced charge separation. To realize an efficient photovoltaic device, a large interfacial area at which effective dissociation of excitons occurs must be created; thus an electron donor material is mixed with an electron acceptor material. (Here, an exciton is a mobile combination of an electron and a hole in an excited crystal, e.g., a semiconductor.) Luminescent compounds as semiconductors are advantageous due to their long lifetime, efficiency, low operating voltage and low cost.

The molecular design of compounds of general formula (10) was intended to achieve high-energy blue phosphorescence with maximum quantum yield (Φ _Ρ ). The C ^A N chelate backbone of the phenyl-triazolyl ligand presents a strong ligand field to the Pt(ll) centre, raising the energy of non-radiative d-d excited states and reducing thermal quenching. The stabilizing ring provides good solubility as well as solution- and solid-state stability, while its rigid structure and high triplet energy level help to increase Φ _Ρ .

As show in Tables herein, doped PMMA films (5 or 10 wt%, as indicated) of Pt(ll) complexes of general formula (10) exhibited good quantum yields. Such complexes displayed bright phosphorescence with emission colors ranging from blue, green, yellow, orange, and red.

Certain embodiments of the invention provide compounds suitable for use in biological and/or medical imaging. For example, such compounds' luminescent properties can be used in cells (in vivo or in vitro) to visualize structures such as tumours or other anomaly.

Certain embodiments of the invention provide compounds suitable for use as neoplastic agents either alone or in conjunction with another neoplastic agents, another pro-apoptotic agent, chemotherapeutic agent, and/or other cancer therapy. Accordingly, certain compounds of general formula (10) or a salt thereof can be administered to a mammal (e.g., human) in a therapeutically effective amount to treat a susceptible neoplasm in a mammal in need thereof.

General structure (200), showing structural features of cyclometalating ligands described herein, is provided below:

(200) wherein R, k, h, m and j are as defined for general formula (100).

Notably, B (boron) is sterically sheltered to protect it from nucleophilic attack, so there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack by, for example, water. If there is only one substituent ortho to B then that substituent is branched C ₃ , branched C ₄ , or linear or branched C ₅ -or higher. A dotted line in a ring indicates that it can be saturated, unsaturated, aromatic or non-aromatic. A substituent can be further substituted. In certain embodiments, compounds of general formula 200 are luminescent (i.e., fluorescent).

In certain embodiments, boron disubstituted by respective substituted aryl carbocyclic moities (e.g., BMes ₂ ) is a substituent of the cyclometalating ligand either at the ring 1 of general formula (200), at ring 2, or at both ring 1 and at ring 2. In some embodiments, this type of substituted cyclometalated ligand has phosphorescent properties. In certain embodiments, this type of substituted ligand is a blue phosphorescent compound. Also, when this type of substituted cyclometalating ligand is used to form a compound of general formula (10), a highly efficient phosphorescent Pt(ll) compound can be achieved. In some embodiments, the phosphorescence is blue.

In some embodiments of general formula (200), the invention provides a compound wherein the boron moiety is substituted by two mesityl groups. The effect of the presence of such substituents (i.e., boron disubstituted by respective substituted aryl carbocyclic moities (e.g., BMes ₂ )) on the N,C-chelate backbone plays several important roles in the high performance of the resulting Pt(ll) compounds of general formula (100) in PhOLEDs. It facilitates the mixing of the ³ LC and the MLCT state, thus enhancing the intrinsic phosphorescent efficiency of the molecule. It minimizes intermolecular interactions, thus enhancing emission efficiency in the solid state. Also, it facilitates electron injection into the emissive layer/dopant, thus improving the device efficiency. In certain embodiments of the invention, such compounds exhibit intense luminescence, which may be photoluminescence and/or electroluminescence.

Importantly, when a B(Mes) ₂ moiety is bound to ring 1 (of general formula (100) at the para position relative to Pt, the compound's luminescence is blue in colour. When a B(Mes) ₂ moiety is bound to ring 1 at the meta position relative to Pt, the compound's luminescence is green, or greenish blue in colour. When a B(Mes) ₂ moiety is bound to ring 1 at the meta position relative to Pt, and ring 2 contains two fused aryl rings, then the compound's luminescence is yellow, orange or red in colour.

Other embodiments of the invention provide compounds that are water-soluble.

Embodiments of the invention further provide methods of applying compounds as described herein to a surface. These methods include solvent cast from solution, electrochemical deposition, vacuum vapor deposition, chemical vapor deposition, spin coating and dip coating. The compounds may be applied alone or with a carrier. In some embodiments of the invention, they are applied in a composition including an organic polymer. Such compositions are also encompassed by the invention. As an example of this application, compounds of general formula (10) form a clear transparent solution with the weakly-luminescent polymer PMMA. This can be converted to a transparent film by evaporating the toluene solvent via either a dip-coating or spin-coating process. Films obtained in this way are stable. Certain polymers such as, for example, PVK, are expected to further enhance the luminescence of an emitter in the film. Conveniently, spin coating may be performed using a Chemat Technology spin-coater KW-4A; and vacuum deposition may be performed using a modified Edwards manual diffusion pump.

Certain compounds of the invention have high chemical and/or thermal stability. As a result, they are suitable for vacuum deposition methods used in fabricating single- or multi-layer OLED devices.

As show in Table 4A, doped PMMA films ( 0 wt%) of BC1 and BC2 exhibit good quantum yields of 90 and 86%, respectively, compared to only 13% for an analogous control compound lacking the BMes ₂ group. The solid-state quantum yield of BC2 represents the highest observed for a blue phosphorescent Pt(ll) complex. BC1 exhibits blue-green phosphorescence in the solid state and solution, with an emission maximum of 478 nm in CH ₂ CI ₂ . This emission is blue-shifted by 20 nm in BC2, resulting in sky-blue emission from the complex at A _max = 462 nm (see Fig. 20-23 and Tables 4A and 4B).

The invention provides a method of producing electroluminescence comprising the steps of: providing an electroluminescent compound of the invention having general formula 100 or general formula 200; and applying a voltage across said electroluminescent compound so that the compound electroluminesces.

According to the invention, electroluminescent devices for use with an applied voltage are provided. In general, such a device has a first electrode, an emitter which is an electroluminescent compound of the invention, and a second, transparent electrode, wherein a voltage is applied between the two electrodes to produce an electric field across the emitter of sufficient strength to cause the emitter to electroluminesce. Preferably, the first electrode is of a metal, such as, for example, aluminum, which reflects light emitted by the compound; whereas the second, transparent electrode permits passage of emitted light therethrough. The transparent electrode is preferably of indium tin oxide (ITO) glass, flexible polymer, or an equivalent known in the art. Here, the first electrode is the cathode and the second electrode is the anode.

In some embodiments of the invention, an EL device includes one or more charge transport layers interposed between the emitter and one or both of the electrodes. Such charge transport layer(s) are employed in prior art systems with inorganic salt emitters to reduce the voltage drop across the emitter. In a first example of such a device, layers are arranged in a sandwich in the following order: first electrode, charge transport layer, emitter and host, second charge transport layer, and second transparent electrode. In

anembodiment of this type, a substrate of glass, quartz or the like is employed. A reflective metal layer (corresponding to the first electrode) is deposited on one side of the substrate, and an insulating charge transport layer is deposited on the other side. The emitter layer which is a compound of the invention is deposited on the charge transport layer, preferably by vacuum vapor deposition, though other methods may be equally effective. A transparent conducting electrode (e.g., ITO) is then deposited on the emitter layer. An effective voltage is applied to produce electroluminescence of the emitter.

In a second example of an EL device of the invention, a second charge transport layer is employed, and the sandwich layers are arranged in the following order: first electrode, first charge transport layer, emitter and host, second charge transport layer and second, transparent electrode.

Electroluminescent devices of the invention may include one or more of the emitting compounds described herein. In some embodiments of the invention, an electroluminescent device such as a flat panel display device may include not only a blue- or green-emitting phosphor as described herein, but may be a multiple-color display device including one or more other phosphors. The other phosphors may emit in other light ranges, e.g., red, green, and/or be "stacked" relative to each other. Convenient materials, structures and uses of electroluminescent display devices are described in Rack, P.D.; Naman, A.; Holloway, P.H.; Sun, S.-S.; and Tuenge, R. T. Materials used in electroluminescent displays." MRS Bulletin (1996) 21 (3): 49-58.

For photoluminescence, the compounds absorb energy from ultraviolet radiation and emit visible light near the ultraviolet end of the visible spectrum, e.g., in the blue region. For electroluminescence, the absorbed energy is from an applied electric field.

The invention further provides methods employing compounds of the invention to harvest photons, and corresponding devices for such use. Spectroscopic studies have demonstrated that compounds of the invention have high efficiency to harvest photons and produce highly polarized electronic transitions. In general, when such compounds are excited by light, a charge separation occurs within the molecule; a first portion of the molecule has a negative charge and a second portion has a positive charge. Thus the first portion acts as an electron donor and the second portion as an electron acceptor. If recombination of the charge separation occurs, a photon is produced and luminescence is observed. In photovoltaic devices, recombination of the charge separation does not occur; instead the charges move toward an anode and a cathode to produce a potential difference, from which current can be produced.

Molecules with the ability to separate charges upon light initiation are useful for applications such as photocopiers, photovoltaic devices and photoreceptors.

Photoconductors provided by the present invention are expected to be useful in such applications, due to their stability and ability to be spread into thin films. Related methods are encompassed by the invention.

Organic semiconducting materials can be used in the manufacture of photovoltaic cells that harvest light by photo-induced charge separation. To realize an efficient photovoltaic device, a large interfacial area at which effective dissociation of excitons occurs must be created; thus an electron donor material is mixed with an electron acceptor material. (Here, an exciton is a mobile combination of an electron and a hole in an excited crystal, e.g., a semiconductor.) Luminescent compounds as semiconductors are advantageous due to their long lifetime, efficiency, low operating voltage and low cost.

Photocopiers use a light-initiated charge separation to attract positively-charged molecules of toner powder onto a drum that is negatively charged.

The molecular design of compounds of general formula (10) was intended to achieve high-energy blue phosphorescence with maximum quantum yield (Φ _Ρ ). The C ^A C or N ^A C chelate backbone presents a strong ligand field to the Pt(ll) centre, raising the energy of non-radiative d-d excited states and reducing thermal quenching. An acetylacetonate (acac) stabilizing ring (ring 3) provides good solubility as well as solution- and solid-state stability, while its rigid structure and high triplet energy level help to increase Φ _Ρ . The BMes ₂ group and related BAr ₂ groups on ring 1 serve to greatly enhance metal-to-ligand charge-transfer phosphorescence.

As described herein, compounds of general formula (100) including

triarylboron-functionalized metal-carbene and triarylboron-functionalized metal-triazole complexes have been prepared and tested. It has been shown that the boron moiety enhanced the phosphorescent quantum yield of such complexes.

Referring to Fig. 1 , an embodiment of an electroluminescent device of the invention is shown. In general, when a potential is applied across an OLED, holes are said to be injected from an anode into a hole transporting layer (HTL) while electrons are injected from a cathode into an electron transporting layer (ETL). The holes and electrons migrate to an ETL/HTL interface. Materials for these transporting layers are chosen so that holes are preferentially transported by the HTL, and electrons are preferentially transported by the ETL. At the ETL/HTL interface, the holes and electrons recombine to give excited molecules which radiatively relax, producing an EL emission that can range from blue to near-infrared (Koene, B.; Loy, D.; and Thompson, M. Unsymmetrical Triaryldiamines as Thermally Stable Hole Transporting Layers for Organic Light-Emitting Devices. Chemistry of Materials. ( 998) 10(8): 2235-2250).

As shown in Fig. 1 , the electron transport material is adjacent to the first electrode (the cathode, which can be, for example, LiF/Aluminum,). The emitter is doped in a host layer, which can be, for example, 4,4'-/V,A/-dicarbazolebiphenyl (CBP) or

tris(4-carbazoyl-9-ylphenyl)amine (TcTa). The hole transport material (for example,

A/,/\/-di-[(1-naphthalenyl)-A/ _; /V-diphenyl]-(1 ,1 '-biphenyl)-4,4'-diamine (NPB),) is placed between the ITO electrode (the anode) and the emitting layer. The choice of the materials employed as charge transport layers and host layers will depend upon the specific properties of the particular emitter employed. The hole transport layer or the electron transport layer may also function as a host layer. The device is connected to a voltage source such that an electric field of sufficient strength is applied across the emitter. Light, preferably blue light, consequently emitted from the compound of the invention passes through the transparent electrode.

As shown in Figs. 2-1 1 , 19 and 24-29 and the Tables provided herein, compounds of general formula (10) exhibit emission in PMMA films doped with 5% or 10% of specified compounds.

As shown in Figs. 12-18 and 34-38, X-ray crystallography studies have confirmed the structural formulae of representative example of compounds of general formula (10) prepared as described in the Working Examples.

Referring to Fig 20, absorption and emission spectra of BC1 and BC2 are shown. Referring to Fig. 34 and 35, single crystals of both BC1 and BC2 were successfully obtained and were examined by X-ray diffraction analyses. The resultant crystal structures of BC1 and BC2 are shown. Both molecules display highly planar geometries about the Pt(ll) centre with minimal strain apparent in either structure, important for the maximization of phosphorescent quantum yields. Strength of the carbene donor (carbene is ring 2 of general formula 100 for BC1 and BC2) is evident in both cases, exhibiting C - Pt bond lengths shorter than those observed between the Pt(ll) centre and the phenyl ring (ring 1 of general formula 100). The considerable trans influence of the carbene can also be observed, with the Pt-0 bond trans to the carbene lengthened by as much as 0.05 A relative to more common nitrogen donors in similar N ^A C chelate cyclometalated systems (see Hudson, Z. M.; et al. Adv. Fund Mater. 2010, 20, 3426). The crystal structures of both BC1 and BC2 show discrete dimeric Pt-Pt stacking, with Pt - Pt distances of 3.389(2) and 3.505(2) A, respectively (for more detailed information see Supporting Materials of Hudson, Z.M.; et al. J. Am. Chem. Soc. (2012) 134: 13930-13933).

In Fig. 21 , current efficiencies for OLEDs based on BC1 and BC2 are graphically displayed. In Fig. 22, power efficiencies for OLEDs based on BC1 and BC2 are shown. As shown, compounds of the invention display excellence current and power efficiencies. In Fig. 23, cyclic voltammetry diagrams of BC1 and BC2 are shown, which provide insight into the HOMO and LUMO levels.

Referring to Fig. 24-29, emission spectra are shown for compounds C1 , C2, C3, C4, C5, C6 at 5% and 10% in PMMA, C8, C9, C10, C11 at 5% in PMMA, C12 at 1 %, 5% and 10% doping level in PMMA, and C27 at 5% and 10% in PMMA.

Referring to Fig. 30-31 , absorption and emission spectra of compound Pt-12 are shown, respectively.

Referring to Fig. 32, an electroluminescence spectrum is shown for compound 06 doped at 5% in a TcTa (tris(4-carbazoyl-9-ylphenyl)amine) host layer.

As shown in Table 3, BMes ₂ -functionalized triazole chelate Pt(ll) compounds and BMes ₂ -functionalized benzimidazolyl chelate Pt(ll) compounds display bright

phosphorescence with emission colors ranging from blue to yellow or orange.

As shown in Fig. 32-33, preliminary electroluminescent property evaluation indicated that BMes ₂ -functionalized triazole chelate Pt(ll) compounds are very promising as phosphorescent emitters in OLEDs. Referring to Fig. 33, a plot is shown presenting EQE versus luminance from compound C6. The CLE. coordinate for compound C6 was found to be (0.178, 0.197).

Referring to Fig. 44, compounds Pt-9 and Pt-1 10 were chosen for EL evaluation, since Pt-9 was the most efficient blue phosphorescent emitter and had the least tendency to form excimer emission among the Pt(Bptrz)(pytrz) compounds. Pt-1 10 was a deep blue emitter but showed a tendency to form an excimer. Its emission of white light with good quantum efficiency made it a candidate for use as a single dopant in white light OLEDs. Both Pt-9 and Pt-1 10 displayed a high thermal stability with the decomposition temperature being > 280°C for Pt-9 and ~250°C for Pt-1 10, based on DSC data.

EL device structures that were used to evaluate Pt-9 and Pt-1 10 are shown in Fig. 44. For the electron transporting layer, both TPBi and TmPyPb were used and their stutures are shown in Fig. 44. For the hole transport layer, TAPc was used because its energy levels match well those of the host materials. Both CDBP and 26mCPY were chosen as the host materials because of their high triplet energies (3.0 eV and 2.9 eV, respectively). For compound Pt-9, 26mCPY was found to be a better host than CDBP while for Pt-1 10, CDBP was found to produce more efficient devices than 26mCPY. Based on the photoluminescent data, EL devices with doping level at 2%, 5% and 10% for 9, and at 2% and 5% for Pt-1 10 were fabricated with the aim to achieve blue and white EL. An EL spectrum of a 5% device of Pt-9 matched very well with the PL spectrum in 5 wt% PMMA or 26mCPY, producing a sky blue color with λ _βπ1 = 467 nm and CIE(xy) of 0.19, 0.34. At 10% doping level, although the EL spectrum of Pt-9 was still dominated by the monomer peak at 467 nm, a large excimer peak at -555 nm appeared, which was again in agreement with the PL spectrum at the same doping level. As a consequence, this EL device produced a white color with CIE (xy) of 0.31 , 0.44. For compound Pt-1 10, at the 2% doping level, the monomer blue peak at 456 nm dominates the EL spectrum while the contribution of the excimer peak at ~555 nm was significant, leading to a white color with CIE (xy) of 0.32, 0.42. At 5% doping level, the EL spectrum of Pt-1 10 was dominated by the excimer peak, producing a yellowish white color with CIE (xy) shifting to 0.38, 0.48. The general trend of the EL spectral dependence of Pt-1 10 on the dopping level was in agreement with that of PL in PMMA films. However, it appeared that Pt-1 10 was more prone to excimer formation in the EL device than in PMMA since it had a greater excimer contribution at the same doping level in the device than in PMMA. In addition, the external quantum efficiency of EL devices of Pt-9 and Pt-110 increased significantly with the doping level, which contradicted the trend observed for PL that decreases in efficiency with increasing doping concentration. This could be caused by more efficient exciton confinement to the excimer than the monomer emission in the device. The other possible explanation is the reduced host triplet-triplet annihilation (TTA) with increasing doping concentration, leading to higher device efficiency. All devices have a low turn-on voltage of 3.0 - 3.2 V. The white 10% EL device of Pt-9 had a good performance with a maximum brightness of 3220 cd/m ² and an external quantum efficiency of 15.6 at 100 cd/m ² . Although many examples of efficient white electrophosphorescent devices are known previously, the majority of them use either multiple dopants or tandem device structures. Efficient white electrophosphorescent devices based on single dopant remain relatively rare. The performance of the 10% EL device of Pt-9 is certainly among the most efficient single-dopant white EL devices.

The following working examples further illustrate the present invention and are not intended to be limiting in any respect.

WORKING EXAMPLES

All reactions were carried out under air unless otherwise noted. Reagents were purchased from Aldrich chemical company (Oakville, ON, Canada) and used without further purification. Solvents were freshly distilled over appropriate drying reagents. The following starting materials were prepared according to literature procedures:

4- dimethylamino-2-phenylpyridine (D. Di Censo et al., Inorg. Chem. 2008, 47, 980-989);

5- (dimesitylboryl)-2-phenylpyridine (Z. M. Hudson et al., Adv. Funct. Mater. 2010, 20, 3426-3439); 5-dimesitylboryl-4-(A/-(1-naphthyl)-A/-phenylamino)phenylpyr idine (Z. M. Hudson et al., Chem. Commun. 2011 , 47, 755-757); 2-(2-pyridyl)indole (T. M. McCormick et al., Org. Lett. 2007, 9, 4087-4090); 1 -naphthyldiphenylphosphine (C. Lin, Y. er al., Dalton Trans. 2011 , 40, 1 132-1 143); (1-methyl-3-phenylimidazol-2-ylidine)silver iodide (C. P. Newman er al., J. Organomet. Chem. 2007, 692, 4962-4968); and [PtMe ₂ (SMe ₂ )] ₂ (G. S. Hill er a/., Inorg. Synth. 1998, 32, pp. 149-151 ). 2-(2-pyridyl)benzothiophene, 2-(2-pyridyl)benzofuran, and all other substituted phenylpyridines were prepared by Suzuki coupling of 2-bromopyridine with commercially available boronic acids (O. Lohse et al., Synlett 1999, 1 , 45-48).

Characterization of Pt complexes described herein but that were previously made and characterized using other synthetic strategies, included ¹ H NMR and elemental analysis. These compounds are 1a, 1 b, 2a, 3, 6, 7, 9b (all from J. Brooks et al., Inorg. Chem. 2002, 41 , 3055-3066), 1c (J. Liu et a/., Inorg. Chim. Acta 2009, 362, 575-579), 8a (Z. M. Hudson et a/., Adv. Fund Mater, 2010, 20, 3426-3439), 8b (Z. He et al., Inorg. Chem. 2006, 45

,10922-10937), 8c (Z. M. Hudson et al., Chem. Commun. 201 1 , 47, 755-757), and 11 (Y. Unger et al., Angew. Chem. Int. Ed. 2010, 49, 10214-10216). The remaining novel complexes described herein were characterized by ¹ H and ³ C NMR as well as elemental analysis. Details are provided in the following examples.

Thin Layer Chromatography was carried out on Si0 ₂ (silica gel F254, Whatman). Flash chromatography was carried out on silica (silica gel 60, 70-230 mesh). ¹ H and ¹³ C spectra were recorded on a Bruker Avance 300 spectrometer () operating at 300 and 75.3 MHz respectively. Deuterated solvents were purchased from Cambridge Isotopes (St. Leonard, QC, Canada) and used without further drying. Excitation and emission spectra were recorded using a Photon Technologies International QuantaMaster Model 2

spectrometer (Anaheim, California, USA) UV-visible absorbance spectra were recorded using a Varian Cary 50 UV-visible absorbance spectrophotometer (Varian, Inc. of Agilent Technologies, Mississauga, ON, Canada). Solution quantum yields were calculated using optically dilute solutions (A = 0.1 ) relative to lr(ppy) ₃ (T. Sajoto, P. I. Djurovich, A. B. Tamayo, J. Oxgaard, W. A. Goddard, M. E. Thompson, J. Am. Chem. Soc. 2009, 131, 9813-9822). Data collection for the X-ray crystal structural determinations were performed on a Bruker SMART CCD 1000 X-ray diffractometer with graphite-monochromated Mo K _Q radiation (λ = 0.71073 A) at 298K and the data were processed on a Pentium PC using the Bruker AXS Windows NT SHELXTL software package (version 5.10). Elemental analyses were performed by the University of Montreal Elemental Analysis Laboratory (Montreal, Canada). Melting points were determined on a Fisher-Johns melting point apparatus. Conveniently EL spectra may be obtained using Ocean Optics HR2000; and data involving current, voltage and luminosity may be obtained using a Keithley 238 high current source measure unit.

Example 1. Fabrication on EL Device

Devices are fabricated in a Kurt J. Lesker LUMINOS® cluster tool with a base pressure of ~10 ^~8 Torr without breaking vacuum. The ITO anode is commercially patterned and coated on glass substrates 50 x 50 mm ² with a sheet resistance less than 15 Ω/square. Substrates are ultrasonically cleaned with a standard regiment of Alconox®, acetone, and methanol followed by UV ozone treatment for 15 min. The active area for all devices is 2 mm ² . The film thicknesses are monitored by a calibrated quartz crystal microbalance. Current- Voltage characteristics are measured using a HP4140B picoammeter in ambient air. Luminance measurements and EL spectra are taken using a Minolta LS-1 10 luminance meter and an Ocean Optics USB200 spectrometer with bare fiber, respectively. The external quantum efficiency of EL devices is calculated following standard procedure. Additional details regarding device fabrication and characterization measurements have been described elsewhere (Hudson, Z. et al. J. Am. Chem. Soc. (2012) 134, 13930-13933).

Devices are fabricated by vacuum vapor deposition on ITO-coated glass substrates. Due to the wide bandgaps of these materials, care is taken to ensure that the HOMO and LUMO energy levels of both emitters were contained within the bandgap of the host material, to ensure efficient trapping of both holes and electrons. Furthermore, it is necessary to employ a host material with a sufficiently high triplet level to ensure that excitons within the device were confined to the dopant. Based on these considerations, devices are fabricated using 4,4'-/V,/\/'-dicarbazolylbiphenyl (CBP) as the hole-transport layer, 1 ,3,5-tris(A/-phenylbenzimidazole-2-yl)benzene (TPBI) as the electron-transport layer, and A/,A/'-dicarbazolyl-3,5-benzene (mCP) as host. These devices have a structure of ITO/M0O ₃ (1 nm)/CBP (35 nm)/mCP (5 nm)/mCP:emitter (12%, 15 nm)/TPBI (65 nm)/LiF (1 nm)/AI.

Example 2. Synthesis of diphenylamino functionalized triazole ligands

Diphenylamino functionalized phenyl triazole ligands were prepared by three step reactions shown in Scheme for Example 2, which involved a Sonogashira coupling (step i) and a "click" reaction (step iii).

Example 2A. Synthesis of (4-ethynylphenyl)diphenylamine ("Ph ₂ NPhCCH")

Scheme for Example 2: Synthesis of diphenylamino functionalized triazole ligands. acetylene, PdCI ₂ (PPh ₃ ) ₂ , Cul, Et ₃ N, THF, 80°C, overnight; ii) NaOH, THF/MeOH, RT, 2h; iii) PhCH ₂ N ₃ , Cu(CH ₃ CN) ₄ PF _6> DIPEA, TBTA, DCM, RT.

A 100 mL three-necked round bottomed flask, equipped with a magnetic stir bar and condenser, was charged with ligand (4-bromophenyl)diphenylamine (leftmost compound of the above scheme) (1 g, 3.08mmol), trimethylsilylacetylene (0.6mL, 4.62mmol),

bis(triphenylphosphine) palladium dichloride (0.1 1 g, 0.3mmol), copper iodide (0.03g, 0.15mmol) and 40 mL of degassed THF/triethylamine (v:v= 3: 1 ). The mixture was stirred at 80°C for 20 hours, and then concentrated under reduced pressure. The product was dissolved in dichloromethane solvent. The hydrophobic solvent solution was then

sequentially washed with saturated ammonium chloride solution, brine and water. The combined hydrophobic phase was dried over MgS0 ₄ and filtered through a filter paper. The product was then purified using flash chromatography through silica using 4% ethyl acetate in hexane as eluent. After removal of eluent solvent under reduced pressure, the resulting white solid was dissolved in 10 mL of tetrahydrofuran solvent and treated with sodium hydroxide in methanol (20 mL of a 2.0 M solution). After stirring for 2 hour, the resulting mixture was concentrated under reduced pressure. After extraction with dichloromethane, the hydrophobic solution was dried over MgS0 ₄ , filtered and the solvent was removed under reduced pressure to give the product (4-ethynylphenyl)diphenylamine ("Ph ₂ NPhCCH") (middle compound of Scheme for Example 2) as a white solid (0.5g, 60%). Yield 60%.

Example 2B. Synthesis of N,N-diphenyl-4-(1-benzyl-1 H-1 ,2,3-triazol-4-yl) aniline, see step (iii) of Scheme for Example 2: To a 50 mL Schlenk flask equipped with a magnetic stir bar was added (4-ethynylphenyl)diphenylamine (0.5g, 1.86mmol), benzyl azide (0.29g, 2.21 mmol), diisopropylethylamine (0.475g, 3.68mmol),

tris[(1-benzyl-1 -/-1 ,2,3-triazol-4-yl)methyl]amine (1 mol %) and 30 mL of dichloromethane. The resulting solution was bubbled with nitrogen gas for 20 minutes. [Cu(CH ₃ CN) ₄ ]PF ₆ (1 mol %) was added as a catalyst. The resulting mixture was stirred overnight, after which the solvent was removed under reduced pressure. The crude product was dissolved in dichloromethane. The solution was washed with saturated ammonium chloride solution, brine and water. Following isolation, the non-aqueous phase was dried over MgS0 ₄ and filtered through a filter paper. The product was then purified using flash chromatography through silica (1 :1 hexanes:ethyl acetate as eluent) to afford 0.54 g

N,N-diphenyl-4-(1 -benzyl-1 H-1 ,2,3-triazol-4-yl) aniline as white solid (72% yield). ¹ H NMR (300 MHz, CDCI ₃ ) δ 7.68 (d, J = 8.8 Hz, 2H), 7.60 (s, 1 H), 7.45-7.36 (m, 3H), 7.35-7.20 (m, 6H), 7.19-6.98 (m, 8H), 5.59 (s, 2H).

Example 3. Synthesis of substituted or unsubstituted phenyl-1 ,2,3-triazole ligands A general scheme is presented in Scheme for Example 3 for synthesis of substituted or unsubstituted phenyl-1 ,2,3-triazoles. For an exemplary specific experimental procedure, see Example 3A. Alternative phenyl-1 ,2,3-triazoles can be synthesized using the procedure of Example 3A by making the following substitutions in the syntheses:

3-ethynyltoluene can be replaced by phenyl acetylene to make

4-phenyl-1-benzyl-1 ,2,3-triazole;

benzyl bromide can be replaced by methyl iodide to make

4-phenyl-1 -methyl-1 ,2,3-triazole; and

3-ethynyltoluene can be replaced by 2,4-difluorophenyl acetylene to make

4-(1 -(2,4-difluorophenyl))-1-benzyl-1 ,2,3-triazole.

All other reactants are the same as described in Example 3A.

R ₃ = H, F

R ₄ = Methyl, Benzyl

Scheme for Example 3: One pot procedure for the synthesis of substituted or unsubstituted phenyl-1 ,2,3-triazole ligands i) Methyl iodide or benzyl bromide , NaN ₃ , Cul, water, 50°C, overnight

Example 3A. Synthesis of 4-(m-tolyl)-1-benzyl-1,2,3-triazole

To a 50 mL pressure tube equipped with a magnetic stir bar was added 3-ethynyltoluene

(1 g, 8.61 mmol), benzyl bromide (1 .62g, 9.47mmol), sodium azide (0.62g, 9.54mmol), copper iodide (0.041g, 0.21 mmol) and 5 mL water. The pressure tube was sealed and the resulting mixture was stirred overnight at 50 °C, after which a crude product precipitate was isolated by filtration. The crude product was dissolved in dichloromethane. The dichloromethane solution was washed with saturated ammonium chloride solution, brine and water. Following isolation, the non-aqueous phase was dried over MgS0 ₄ and filtered through a filter paper. After removal of the solvent, 4-(m-tolyl)-1 -benzyl-1 ,2,3-triazole (where, in the product of Scheme for Example 3, R ¹ is H, R ³ is H, R ² is methyl, and R ⁴ is benzyl) (1.12 g) was obtained as white solid (52% yield). Characterization of this compound matched its previously published information (see cNulty, J. ef a/., Eur. J. Org. Chem. 2012, 5462).

Characterization data for alternative phenyl-1 ,2,3-triazoles (as discussed above): 4-phenyl-1-benzyl-1 ,2,3-triazole: see McNulty. J. ef a/., Eur. J. Org. Chem. 2012, 5462; 4-phenyl-1 -methyl-1 ,2,3-triazole: see Uppal, Baljinder S. et al., Dalton Transactions, 201 1 , 7610; and 4-(1-(2,4-difluorophenyl))-1-benzyl-1 ,2,3-triazole ("F2Ph-Bn"): Yield 51 %. ¹ H NMR (300 MHz, CDCI ₃ ) δ 8.30 (m, 1 H), 7.83 (d, J = 3.7 Hz, 1 H), 7.49-7.23 (m, 4H), 7.00 (m, 1 H), 6.89 (ddd, J = 1 1.0 Hz, 8.7 Hz, 2.4 Hz, 1 H), 5.61 (s, 2H). Also, see Botelho, Moema de Barros e Silva ef a/., Journal of Materials Chemistry, 2011 , 8829.

Example 3B. Synthesis of ((4-ethynylphenyl)methanetriyl)tribenzene

= CH ₂ Ph or CHPh ₂

Scheme for Example 3B: Synthesis of tritylphenyl functionalized triazole ligands. i) TMS acetylene, PdCI ₂ (PPh ₃ ) ₂ , Cul, Et ₃ N, THF, 80 °C, overnight; ii) NaOH, THF/MeOH, RT, 2h; iii) PhCH ₂ N ₃ or Ph ₂ CHN ₃ , Cu(CH ₃ CN) ₄ PF ₆ , DIPEA, TBTA, DCM, RT

A 100 mL three-necked round bottomed flask, equipped with a magnetic stir bar and condenser, was charged with ((4-iodophenyl)methanetriyl)tribenzene (1.47 g, 3.29 mmol), trimethylsilylacetylene (0.7mL, 5.39 mmol), bis(triphenylphosphine) palladium dichloride (0.116g, 0.3 mmol), copper iodide (0.031g, 0.15mmol) and 40 ml. of degassed

THF/triethylamine (v:v- 3:1 ). See steps (i) and (ii) of Scheme for Example 3B. The mixture was stirred at 80°C for 20 hours, and then concentrated under reduced pressure. The product was dissolved in dichloromethane solvent. The hydrophobic solvent solution was then sequentially washed with saturated ammonium chloride solution, water and brine. The combined hydrophobic phase was dried over MgS0 ₄ and filtered through a filter paper. The product was then purified using flash chromatography through silica using 1 :5

dichloromethane:hexane as eluent. After removal of eluent solvent under reduced pressure, the resulting white solid was dissolved in 10 mL of tetrahydrofuran solvent and treated with sodium hydroxide in methanol (20 mL of a 2.0 M solution). After stirring for 2 hour, the resulting mixture was concentrated under reduced pressure. After extraction with

dichloromethane, the hydrophobic solution was dried over MgS0 ₄ , filtered and the solvent was removed under reduced pressure to give the product

((4-ethynylphenyl)methanetriyl)tribenzene as a white solid (0.84g, 74%).

Example 3C. Synthesis of 1-benzyl-4-(4-tritylphenyl)-1 H-1 ,2,3-triazole see step (Mi) of Scheme for Example 3B

To a 50 mL Schlenk flask equipped with a magnetic stir bar was added

((4-ethynylphenyl)methanetriyl)tribenzene (0.7g, 2.03 mmol), benzyl azide (0.33g, 2.54 mmol), diisopropylethylamine (0.52 g, 4.06 mmol), tris[( 1 -benzyl- 1 H-1 ,2,3-trrazol-4-yl) methyl]amine (1 mol %) and 30 mL of dichloromethane. The resulting solution was bubbled with nitrogen gas for 20 minutes. [Cu(CH ₃ CN) ₄ ]PF ₆ (1 mol %) was added as a catalyst. The resulting mixture was stirred overnight, after which the solvent was removed under reduced pressure. The crude product was dissolved in dichloromethane. The solution was washed with saturated ammonium chloride solution, brine and water. Following isolation, the non-aqueous phase was dried over MgS0 ₄ and filtered through a filter paper. The product was then purified using flash chromatography through silica (3:1 hexanes:ethyl acetate as eluent) to afford 0.60 g 1-benzyl-4-(4-tritylphenyl)-1 H-1 ,2,3- triazole (shown as Ph3CPh-Bn below) as white solid (62% yield).

Notably, the above synthetic procedure could also be used to synthesize

1-benzhydryl-4-(4-tritylphenyl)-1 H-1 ,2,3-triazole (shown as Ph3CPh-CHPh2 below) when (azidomethylene)dibenzene is used instead of benzyl azide.

Ph3CPh-Bn Ph3CPh-CHPh2

Ph3CPh-Bn: Yield 62%. ¹ H NMR (300 MHz, CDCI ₃ ) δ 7.79 (d, J = 8.3 Hz, 2H), 7.63 (s, 1 H), 7.45-7.10 (m, 22H)„ 5.59 (s, 2H).

Ph3CPh-CHPh2: Yield 71 %. ¹ H NMR (300 MHz, CDCI ₃ ) δ 7.71 (d, J = 8.0 Hz, 2H), 7.59 (s, 1 H), 7.45-7.10 (m, 28H)

Example 4. Synthesis of the Pt(ll) compounds

Example 4A. Synthesis of the Pt(ll) compounds of general formula (1)

Triazole ligand (0.10 mmol) (see previous Examples) and [PtMe ₂ (u-SMe ₂ )] ₂ (0.032 g, 0.055 mmol) were added to a 20 mL screw-cap vial with 5 mL of acetone.

Scheme for Example 4A: Synthesis of Pt(ll) compounds, i) [PtMe ₂ (u-SMe ₂ )] ₂ , acetone, 65 °C, 2-3h; ii) p-toluenesulfonic acid, THF, 1 h; iii) Ν ^Λ ΝΗ ligand, overnight.

The mixture was heated at 65°C for 2 hours before 1 mL of 0.1 M solution of TsOH in THF was added. The resulting solution was stirred for 1 hour, then 0.1 1 mmol of the corresponding Ν ^Λ ΝΗ ancillary ligand was added and the mixture was stirred overnight. After the solvent was removed under reduced pressure, the product was extracted with

dichloromethane, and then washed with brine and water. The combined organic phase was dried over MgSQ ₄ , filtered and purified on silica. Pt(ll) complexes as described herein were given a shorthand nickname, as indicated below.

Characterization data for Pt(ll) complexes:

Pt-(Ph2NPh-Bn) (t-Bu-trz) ("T1 "): Yield 20%. H NMR (300 MHz, CD ₂ CI ₂ ) δ 9.39 (d, J = 5.9 Hz, 1 H), 8.85 (s, 1 H), 7.78 (s, 1 H), 7.51 -7.26 (m, 6H), 7.25-6.98 (m, 10H), 6.90 (t, J = 7.2 Hz, 2H), 6.70 (d, J = 8.2 Hz, 1 H), 5.51 (s, 2H), 2.40 (s, 3H), 1.06 (s, 9H).

Pt-(Ph2NPh-Bn) (CF ₃ -trz) ("T2"): Yield 14%. ¹ H NMR (400 MHz, CD ₂ CI ₂ ) δ 9.42 (d, J = 5.6 Hz, 1 H), 8.51 (d, J = 2.3 Hz, 1 H), 7.84 (s, 1 H), 7.40 (s, 1 H), 7.39-7.31 (m, 5H), 7.27-7.14 (m, 5H), 7.12-7.01 (m, 5H), 6.96 (t, J = 7.3 Hz, 2H), 6.75 (dd, J = 8.2 Hz, 2.1 Hz, 1 H), 5.51 (s, 2H), 2.41 (s, 3H).

Pt-(Ph-Bn) (t-Bu-trz) ("T3"): Yield 23%. H NMR (300 MHz, CD ₂ CI ₂ ) δ 9.35 (d, J = 4.9 Hz, 1 H), 9.00 (d, J = 7.7 Hz, 1 H), 7.81 (s, 1 H), 7.49-7.26 (m, 6H), 7.25-6.95 (m, 4H), 5.49 (s, 2H), 2.41 (s, 3H), 1.40 (s, 9H). Pt-(Ph-Bn) (CF ₃ -trz) ("T4"): Yield 17%. ¹ H NMR (400 MHz, CD ₂ CI ₂ ) δ 9.32 (d, J = 5.6 Hz, 1 H), 8.69 (d, J = 7.6 Hz, 1 H), 7.79 (s, 1 H), 7.45-7.29 (m, 6H), 7.18 (d, J = 5.6 Hz, 1 H), 7.14 ( dd, J = 7.3 Hz, 1.3 Hz, 1 H), 7.08 ( td, J = 7.5 Hz, 1.5 Hz, 1 H), 7.01 ( td, J = 7.3 Hz, 1.1 Hz, 1 H), 5.51 (s, 2H), 2.41 (s, 3H). Pt-(Ph-Me) (t-Bu-trz) ("T5"): Yield 15%. ¹ H NMR (400 MHz, CD ₂ CI ₂ ) δ 9.35 (d, J = 5.8 Hz, 1 H), 9.00 (d, J = 7.3 Hz, 1 H), 7.80 (s, 1 H), 7.52 (s, 1 H), 7.27 (s, 1 H), 7.16-7.09 (m, 2H), 7.04 (t, J = 7.2 Hz, 1 H), 4.08 (s, 3H), 2.41 (s, 3H), 1 .40 (s, 9H).

Pt-(MePh-Bn) (CF ₃ -trz) ("T6"): Yield 8%. ¹ H NMR (400 MHz, CD ₂ CI ₂ ) δ 9.44 (d, J = 5.6 Hz, 1 H), 8.59 (d, J = 7.6 Hz, 1 H), 7.89 (s, 1 H), 7.48 (s, 1 H), 7.43-7.31 (m, 5H), 7.26 (d, J = 5.3 Hz, 1 H), 7.06 (s, 1 H), 6.97 (d, J = 7.8 Hz, 1 H), 5.55 (s, 2H), 2.44 (s, 3H), 2.24 (s, 3H).

Pt-(F2Ph-Bn) (t-Bu-trz) ("T7"): Yield 39%. H NMR (400 MHz, CD ₂ CI ₂ ) δ 9.26 (d, J = 5.8 Hz, 1 H), 8.66 (dd, J = 10.2 Hz, 2.4 Hz, 1 H), 7.77 (s, 1 H), 7.47 (d, J = 1.1 Hz, 1 H), 7.41 -7.30 (m, 5H), 7.10 (dd, J = 5.6 Hz, 1.3 Hz, 1 H), 6.51 (ddd, J = 10.0 Hz, 9.0 Hz, 2.4 Hz, 1 H), 5.51 (s, 2H), 2.42 (s, 3H), 1.40 (s, 9H).

Pt-(F2Ph-Bn) (CF ₃ -trz) ("T8"): Yield 46%. HRMS for C ₂₄ H ₁₇ N ₇ F ₅ Pt: calcd. 693.1 1 13, found 693.1 132.

Pt-(F2Ph-Bn) (t-Bu-trz) ("T9"): Yield 48%. ¹ H NMR (300 MHz, CD ₂ CI ₂ ) δ 9.35 (d, J = 6.4 Hz, 1 H), 8.69 (m, 1 H), 7.81 (s, 1 H), 7.60-7.30 (m, 12H), 6.64 (m, 1 H), 5.58 (s, 2H), 4.26 (s, 2H), 2.50 (s, 3H).

Example 4B. Synthesis of the Pt(ll) compounds T14, T15 and T18

Pt-(Ph3CPh-Bn) (CF3-trz) "T18" Pt-(Ph3CPh-CHPh2) (t-Bu-trz) "T14" Pt-(Ph3CPh-CHPh2) (CF3-trz) "T15"

General procedure for the synthesis of Pt(ll) compounds T14, T15, and T18

The phenyltriazole ligand (0.20 mmol) and [PtMe ₂ (SMe ₂ )] ₂ (0.1 1 mmol) were added to a 20 mL screw-cap vial with 5 mL of acetone. The mixture was heated at 70 °C for 3 hours before 1 mL of 0.1 M solution of TsOH in THF was added. The resulting solution was stirred for 1 hour, then 0.22 mmol of corresponding pytrz ligand in acetone was added and the mixture was stirred at RT for 2 days. After the solvent was removed under reduced pressure, the product was extracted with dichloromethane, and then washed with brine and water. The combined organic phase was dried over MgS0 ₄ , filtered and purified on silica.

Pt-(Ph3CPh-Bn)(CF3-trz) "T18": Yield 24%. H NMR (400 MHz, CD ₂ CI ₂ ) δ 9.38 (d, J = 5.8 Hz, 1 H), 8.87 (d, J = 1.8 Hz, 1 H), 7.86 (s, 1 H), 7.45-6.95 (m, 24H), 5.46 (s, 2H), 2.41 (s, 3H).

Pt-(Ph3CPh-CHPh2)(t-Bu-trz) "T14": Yield 22%. ¹ H NMR (400 MHz, CD ₂ CI ₂ ) δ 9.12 (d, J = 5.6 Hz, 1 H), 9.07 (d, J = 1.8 Hz, 1 H), 7.72 (s, 1 H), 7.49 (s, 1 H), 7.45-7.00 (m, 28H), 6.98 (d, J = 4.5 Hz, 1 H), 2.35 (s, 1 H), 1.03 (s, 9H).

Pt-(Ph3CPh-CHPh2)(CF3-trz) "T15": Yield 20%. ¹ H NMR (400 MHz, CD ₂ CI ₂ ) δ 9.16 (d, J = 5.6 Hz, H), 8.87 (d, J = 1 .5 Hz, 1 H), 7.83 (s, 1 H), 7.51 (s, 1 H), 7.45-6.95 (m, 29H), 2.38 (s, 3H).

Example 5. One-Pot Synthesis of Cyclometalated Pt(ll) β-Diketonates

Scheme for Example 5. General Synthesis of Cyclometalated Pt(ll) β-Diketonates

To a 20 mL screw-cap vial equipped with a magnetic stir bar was added one equivalent of a cyclometalating ligand (0.35 mmol), [PtMe ₂ (SMe ₂ )]2 dimer (100 mg, 0.17 mmol), and 3 mL of THF. The resulting mixture was allowed to stir 1 hr at ambient temperature, then a solution of CF ₃ SO ₃ H organic acid (1 mL, 0.35 M in THF) was added dropwise. The mixture was stirred for 30 minutes, then a solution of Na(acac) (0.70 mmol in 2 mL MeOH) was added. The mixture was stirred for 1.5 hours, then partitioned between water and CH ₂ CI ₂ . The hydrophobic layer was washed with brine, dried over MgS0 ₄ , filtered, and concentrated under reduced pressure. The resulting residue was then purified using a plug of silica gel, with hexanes and CH ₂ CI ₂ as eluent, to give analytically pure material.

Characterization Data for Compounds Prepared Using the above general synthesis with the appropriate cyclometalating ligand (structural formulae shown in Table 1).

1a: ¹ H NMR (400 MHz, Chloroform-d) δ 9.00 (d, sat, Jp _t-H = 41.8 Hz, J = 5.8 Hz, 1 H), 7.80 (t, J = 7.8 Hz, 1 H), 7.71 - 7.55 (m, 2H), 7.45 (d, J = 7.6 Hz, 1 H), 7.21 (t, J = 7.4 Hz, 1 H), 7.15 - 7.06 (m, 2H), 5.48 (s, 1 H), 2.01 (s, 6H) ppm, Anal, calc'd for C ₁₆ H ₁₅ N0 ₂ Pt: C 42.86, H 3.37, N 3.12; found C 43.56, H 3.39, N 2.98.

1 b: ¹ H NMR (400 MHz, Chloroform-d) δ 9.00 (d, sat, J _Pt . _H = 40.9 Hz, J = 5.8 Hz, 1 H), 7.81 (t, J = 7.7 Hz, 1 H), 7.67 (d, J = 7.6 Hz, 1 H), 7.63 (d, J = 8.1 Hz, 1 H), 7.45 (d, J = 7.6 Hz, 1 H), 7.22 (t, J = 7.4 Hz, 1 H), 7.16 - 7.07 (m, 2H), 5.82 (s, 1 H), 1.29 (s, 9H), 1.28 (s, 9H) ppm, Anal, calc'd for C ₂ 2H ₂₇ N0 ₂ Pt: C 49.62, H 5.1 1 , N 2.63; found C 49.86, H 5.05, N 2.59.

1c: ¹ H NMR (400 MHz, Chloroform-d) δ 9.15 (d, sat, J _R . _H = 39.0 Hz, J = 5.8 Hz, 1 H), 8.1 1 (d, J = 7.3 Hz, 2H) 8.08 (d, J = 7.1 Hz, 2H), 8.01 (d, J = 7.1 Hz, 1 H), 7.85 (t, J = 7.7 Hz, 1 H), 7.80 (d, J = 7.3 Hz, 1 H), 7.69 (d, J = 8.1 Hz, 1 H), 7.57 (t, J = 7.3 Hz, 2H), 7.51 (t, J = 7.8 Hz, 4H), 7.29 (t, J = 8.3 Hz, 1 H), 7.20 (t, J = 6.1 Hz, 1 H), 7.15 (t, J = 7.5 Hz, 1 H), 6.79 (s, 1 H) ppm, Anal, calc'd for C ₂₆ H ₁₉ N0 ₂ Pt: C 54.54, H 3.35, N 2.45, found C 55.05, H 2.92, N 2.40.

2a: ¹ H NMR (400 MHz, Chloroform-d) δ 8.97 (d, sat, J _Pt - _H = 42.3 Hz, J = 5.8 Hz, 1 H), 7.77 (t, J = 7.7 Hz, 1 H), 7.57 (d, J = 8.0 Hz, 1 H), 7.42 (s, 1 H), 7.34 (d, J = 7.8 Hz, 1 H), 7.07 (dd, J = 7.4, 5.8 Hz, 1 H), 6.92 (d, J = 7.8 Hz, 1 H), 5.48 (s, 1 H), 2.41 (s, 3H), 2.03 (s, 3H), 2.01 (s, 3H) ppm; Anal, calc'd for C ₁₇ H ₁₇ N0 ₂ Pt: C 44.16, H 3.71 , N 3.03; found C 44.99, H 3.61 , N 2.98.

2b: ¹ H NMR (400 MHz, Chloroform-d) δ 9.00 (d, sat, J _Pt . _H = 40.5 Hz, J = 5.8 Hz, 1 H), 7.82 (t, J = 7.8 Hz, 1 H), 7.64 - 7.47 (m, 2H), 7.36 (d, J = 8.3 Hz, 1 H), 7.14 (t, J = 6.6 Hz, 1 H), 7.10 (dd, J = 8.2, 2.1 Hz, 1 H) 5.50 (s, 1 H), 2.04 (s, 3H), 2.02 (s, 3H) ppm; ¹³ C NMR (100 MHz, Chloroform-d) δ 185.8, 184.4, 167.3, 147.3, 143.1 , 141.0, 138.3, 134.8, 130.0, 124.0, 123.6, 121.4, 1 18.5, 102.6, 28.2, 27.1 ppm; Anal, calc'd for C ₁₆ H ₁₄ CIN0 ₂ Pt: C 39.80, H 2.92, N 2.90; found C 40.29, H 2.91 , N 2.68; m.p. > 300 °C. 2c: ¹ H NMR (400 MHz, Chloroform-d) δ 8.99 (d, sat, J _Pt- H = 39.6 Hz, J = 5.8 Hz, 1 H), 7.82 (t, J

= 7.8 Hz, 1 H), 7.72 (d, J = 1.8 Hz, 1 H), 7.58 (d, J = 8.1 Hz, 1 H), 7.32-7.23 (m, 2H), 7.15 (t, J =

6.5 Hz, 1 H), 5.49 (s, 1 H), 2.04 (s, 3H), 2.02 (s, 3H) ppm; ³ C NMR (100 MHz, Chloroform-d) δ 185.8, 184.3, 167.3, 147.3, 143.5, 141.4, 138.3, 132.8, 126.5, 124.2, 123.9, 121.5, 1 18.5, 102.6, 28.2, 27.1 ppm, Anal, calc'd for Ci ₆ Hi ₄ BrN0 ₂ Pt: C 36.45, H 2.68, N 2.66; found C 36.89, H 2.63, N 2,56; m.p. > 300 °C. 3: H NMR (400 MHz, Chloroform-d) δ 9.07 (d, sat, J _R . _H = 40.7 Hz, J = 5.8 Hz, 1 H), 8.04 (d, J = 8.1 Hz, 1 H), 7.88 (t, J = 8.1 Hz, 1 H), 7.32 (dd, J = 8.4, 4.9 Hz, 1 H), 7.24 - 7.17 (m, 1 H), 7.14 - 7.04 (dt, J = 10.9, 8.3 Hz, 1 H), 5.49 (s, 1 H), 2.02 (s, 3H), 2.01 (s, 3H) ppm; Anal, calc'd for C ₁₆ H ₁₃ N0 ₂ FPt: C 39.68, H 2.71 , N 2.89; found C 40.1 1 , H 2.70, N 2.78. 4: ¹ H NMR (400 MHz, Chloroform-d) δ 9.00 (d, sat, J _Pt - _H = 39.8 Hz, J = 5.8 Hz, 1 H), 7.80 (t, J = 7.8 Hz, 1 H), 7.58 (d, J = 8.1 Hz, 1 H), 7.51 (d, J = 8.4 Hz, 1 H), 7.10 (dd, J = 7.3, 5.6 Hz, 1 H), 7.04 (d, J = 2.7 Hz, 1 H), 6.91 (dd, J = 8.3, 2.7 Hz, 1 H), 5.47 (s, 1 H), 3.85 (s, 3H), 2.00 (s, 6H) ppm; ¹³ C NMR (100 MHz, Chloroform-d) δ 185.6, 183.9, 168.0, 157.1 , 147.3, 145.0, 138.1 , 131 .1 , 128.9, 121.3, 1 18.3, 1 15.6, 108.8, 102.5, 55.4, 28.3, 27.1 ppm, Anal, calc'd for C ₁₇ H ₁₇ N0 ₃ Pt: C 42.68, H 3.58, N 2.93; found C 43.19, H 3.55, N 2.79; m.p. 227-228 °C.

5: ¹ H NMR (400 MHz, Chloroform-d) δ 8.41 (d, J = 6.9 Hz, 1 H), 7.58 (d, J = 7.3 Hz, 1 H), 7.37 (d, J = 7.6 Hz, 1 H), 7.15 (t, J = 7.4 Hz, 1 H), 7.05 (t, J = 7.4 Hz, 1 H), 6.74 (d, J = 3.0 Hz, 1 H), 6.34 (dd, J = 7.0, 3.0 Hz, 1 H), 5.43 (s, 1 H), 3.1 1 (s, 6H), 1 .97 (s, 3H), 1.96 (s, 3H) ppm; ¹³ C NMR (100 MHz, Chloroform-d) δ 185.1 , 183.8, 166.7, 155.1 , 146.0, 145.8, 138.1 , 130.5,

128.3, 123.0, 121.9, 103.8, 102.3, 100.2, 39.4, 28.2, 27.2 ppm; Anal, calc'd for C ₁₈ H ₂₀ N ₂ O ₂ Pt: C 43.99, H 4.10, N 5.70; found C 44.99, H 4.15, N 5.68; m.p. 265-266 °C.

6: ¹ H NMR (400 MHz, Chloroform-d) δ 9.14 (d, J = 5.4 Hz, 1 H), 8.26 (d, J = 8.0 Hz, 1 H), 7.85 - 7.73 (m, 2H), 7.63 - 7.57 (m, 2H), 7.53 (d, J = 8.8 Hz, 1 H), 7.44 (dd, J = 8.0, 5.4 Hz, 1 H), 5.54 (s, 1 H), 2.07 (s, 6H) ppm; Anal, calc'd for Ci ₈ H ₁₅ N0 ₂ Pt: C 45.76, H 3.20, N 2.97; found C 46.1 1 , H 3.12, N 2.92.

7: ¹ H NMR (400 MHz, Chloroform-d) δ 9.57 (d, J = 8.9 Hz, 1 H), 8.26 (d, J = 8.7 Hz, 1 H), 7.85 - 7.72 (m, 4H), 7.59 (d, J = 7.7 Hz, 1 H), 7.55 (dd, J = 8.1 , 6.9 Hz, 1 H), 7.23 (d, J = 7.5 Hz, 1 H), 7.17 (t, J = 7.5 Hz, 1 H), 5.58 (s, 1 H), 2.06 (s, 3H), 2.05 (s, 3H) ppm; Anal, calc'd for C ₂₀ H ₁₇ NO ₂ Pt: C 48.19, H 3.44, N 2.81 ; found C 48.47, H 3.28, N 2.67.

8a: ¹ H NMR (400 MHz, Chloroform-d) δ 9.04 (s, sat, J _R-H = 38.4 Hz, H), 7.88 (d, J = 8.0 Hz, 1H), 7.63 (d, J = 7.6 Hz, 1H), 7.57 (d, J = 8.1 Hz, 1H), 7.50 (d, J = 7.8 Hz, 1H), 7.22 (t, J = 7.4 Hz, 1H), 7.10 (t J = 7.5 Hz, 1H), 6.87 (s, 4H), 5.40 (s, 1H), 2.32 (s, 6H), 2.09 (s, 12H), 1.98 (s, 3H), 1.66 (s, 3H) ppm; Anal, calc'd. for C ₃ 4H36B 0 ₂ Pt: C 58.63, H 5.21, N 2,01; found C 57.63, H 5.23, N 1.83.

8b: H NMR (400 MHz, Chloroform-d) δ 8.89 (d, sat, J _R . _H = 39.6 Hz, J = 5.3 Hz, 1H), 7.72 (t, J = 7.6 Hz, 1H), 7.47 (d, J = 7.8 Hz, 1H), 7.32-7.24 (m, 6H), 7.24-7.18 (m, 4H), 7.04 (t, J = 7.2 Hz, 2H), 7.00 (d, J = 6.5 Hz, 1H), 6.69 (dd, J = 8.4, 2.4 Hz, 1H), 5.39 (s, 1H), 1.97 (s, 3H), 1.73 (s, 3H) ppm, Anal, calc'd for C ₂₈ H ₂ 4N ₂ 02Pt: C 54.63, H 3.93, N 4.55; found C 55.31, H 3.94, N 4.35.

8c: ¹ H NMR (400 MHz, Chloroform-d) δ 8.90 (s, sat, J _Pt-H = 35.3 Hz, 1H), 8.01 (d, J = 8.5 Hz, 1H), 7.88 (d, J = 8.2 Hz, 1H), 7.79 (d, J = 8.2 Hz, 1H), 7.75 (d, J = 8.1 Hz, 1H), 7.52- 7.40 (m, 3H), 7.40 - 7.31 (m, 2H), 7.23 (m, 6H), 6.99 (m, 1H), 6.85 (m, 5H), 6.55 (d, J = 8.5 Hz, 1H), 5.31 (s, 1 H) 2.30 (s, 6H), 2.08 (s, 12H), 1.62 (s, 6H) ppm; Anal, calc'd for C ₅₀ H47BN ₂ O ₂ Pt: C 65.72, H 5.18, N 3.07; found C 66.09, H 5.07, N 3.08.

9a: ¹ H NMR (400 MHz, Chloroform-d) δ 8.86 (d, sat, J _Pt-H = 42.8 Hz, J = 5.6 Hz, 1H), 8.08 (d, J = 7.8 Hz, H), 7.73 (t, J = 7.8 Hz, 1H), 7.44 (d, J = 8.3 Hz, 1H), 7.37-7.30 (m, 2H), 7.24 (t, J = 7.3 Hz, 1 H), 7.03 (dd, J = 7.4, 5.8 Hz, 1 H), 5.54 (s, 1 H), 2.06 (s, 3H), 2.03 (s, 3H) ppm ¹³ C NMR (100 MHz, Chloroform-d) δ 185.1, 183.6, 159.5, 156.6, 147.8, 138.9, 133.3, 125.4, 123.7, 122.8, 119.1, 116.6, 116.3, 111.1, 102.5, 28.1, 26.4 ppm; Anal, calc'd for

C ₁₈ H ₁₅ N0 ₃ Pt: C 44.27, H 3.10, N 2.87; found C 44.68, H 2.72, N 2.73; m.p.247-248 °C. 9b: ¹ H NMR (400 MHz, Chloroform-d) δ 8.92 (d, sat, J _Pt . _H = 40.0 Hz, J = 5.8 Hz, 1H), 8.83 - 8.76 (m, 1 H), 7.86 - 7.78 (m, 1 H), 7.72 (t, J = 7.8 Hz, 1 H), 7.40 - 7.28 (m, 4H), 6.96 (dd, J = 7.3, 5.8 Hz, 1H), 5.56 (s, 1H), 2.10 (s, 3H), 2.03 (s, 3H) ppm; Anal, calc'd. for Ci ₈ H ₁₅ N0 ₂ PtS: C 42.97, H 3.00, N 2.78; found C 42.97, H 2.71, N 2.76.

9c: ¹ H NMR (400 MHz, Chloroform-d) δ 8.92 (d, sat, J _Pt . _H = 40.7 Hz, J = 5.8 Hz, 1H), 8.30 (d, J = 7.9 Hz, 1 H), 7.57 (t, J = 7.3 Hz, 2H), 7.49 (t, J = 7.3 Hz, 1 H), 7.43 (d, J = 7.3 Hz, 2H), 7.36 (t, J = 7.9 Hz, 1H), 7.19 (t, J = 7.5 Hz, 1H), 7.11 (t, J = 7.3 Hz, 1H), 7.02 (d, J = 8.3 Hz, 1H), 6.79 (dd, J = 7.3, 5.7 Hz, 1H), 6.38 (d, J = 8.2 Hz, 1H), 5.54 (s, H), 2.09 (s, 3H), 2.02 (s, 3H) ppm; ³ C NMR (100 MHz, Chloroform-d) δ 184.9, 183.5, 159.7, 148.2, 142.6, 142.3, 138.6, 138.1, 132.7, 129.6, 128.2, 127.9, 124.2, 123.6, 120.3, 118.2, 117.2, 116.5, 110.0, 102.4, 28.3, 26.4 ppm, Anal, calc'd for C ₂ 4H2oN ₂ 0 ₂ Pt: C 51.15, H 3.58, N 4.97; found C 51.67, H 3.51 , N 4.73; m.p. > 300 °C.

Pt-Bppy (21 ): Yield: 92%. ¹ H NMR (400 MHz, CD ₂ CI _2> 25 °C, TMS) δ = 9.24 (d, sat, ³ J = 5.6 Hz, Jp _t-H = 36 Hz, 1 H), 7.81 (td, ³ J = 8.0, ⁴ J = 1 .6 Hz, 1 H), 7.65-7.53 (m, 3H), 7.28 (dd, ³ J = 7.6, ⁴ J = 1.2 Hz, 1 H), 7.18 (td, ³ J = 6.4, ⁴ J = 1.2 Hz, 1 H), 6.87(s, 4H), 5.55 (s, 1 H), 2.35 (s, 6H), 2.07 (s, 12H), 2.06 (s, 3H), 2.02 (s, 3H); ¹³ C NMR (100 MHz, CD ₂ CI ₂ , 25 °C, TMS) δ=186.2, 184.4, 167.9, 147.9, 147.2, 144.9, 140.7, 138.2, 131.2, 130.3, 128.2, 128.1 , 121.5, 1 18.6, 102.3, 27.9, 26.9, 23.2, 20.9. Anal. Calcd (%) for C ₃₃ H ₃₅ BN0 ₂ Pt: C, 57.99; H, 5.16; N, 2.05. Found: C, 57.89; H, 5.19; N, 2.08. This product was also obtained when

Pt(phenyl) ₂ (DMSO) ₂ was used in place of [PtMe ₂ (SMe ₂ )] ₂ .

Pt-Bmppy (22): Yield: 89%. ¹ H NMR (400 MHz, CD ₂ CI ₂ , 25 °C, TMS) δ = 9.10 (dd, sat, ³ J = 5.6 Hz, ⁴ J = 1.2 Hz, Jp,. _H = 42 Hz, 1 H), 7.79-7.74 (m, 2H), 7.45 (d, sat, ³ J = 7.7 Hz, J _Pt . _H = 28 Hz, 1 H), 7.05 (td, ³ J = 7.2 Hz, ⁴ J =1.2 Hz, 1 H), 6.84(d, ³ J = 7.6 Hz, 1 H), 6.70 (s, 4H), 5.41 (s, 1 H), 2.40 (s, 3H), 2.20 (s, 6H), 1.93 (s, 12H), 1.87 (s, 3H), 1.45 (s, 3H); ¹³ C NMR (100 MHz, CD ₂ CI ₂ , 25 °C, TMS) δ = 186.3, 184.4, 168.4, 147.8, 146.2, 143.8, 143.4, 140.2, 138.5, 137.9, 134.8, 128.2, 128.0, 123.2, 120.8, 102.2, 28.0, 26.9, 22.8, 20.9. Anal. Calcd (%) for

C34H ₃₇ BN0 ₂ Pt : C, 58.54; H, 5.35; N, 2.01. Found: C, 58.52; H, 5.38; N, 2.05. This product was also obtained when Pt(phenyl) ₂ (DMSO) ₂ was used in place of [PtMe ₂ (SMe ₂ )] ₂ .

Pt-Bfppy (23): Bright yellow crystals were obtained after recrystallization from DCM/hexane. ¹ H NMR (400 MHz, CD ₂ CI ₂ , 25 °C, TMS): δ = 9.1 1 (d, ⁴ = 0.5 Hz, 1 H), 8.02 (d, ³ = 8.5 Hz, 1 H), 7.86 (t, ³ J = 8.0 Hz, 1 H), 7.45 (d, ³ J = 8.5 Hz, 1 H), 7.20 (t, ³ J = 7.5 Hz, 1 H), 7.06 (t, ³ J = 7.5 Hz, 1 H), 6.85 (s, 4H), 5.54 (s, 1 H), 2.33 (s, 6H), 2.10 (s, 12H), 1.75 (s, 3H), 1.15 (s, 3H). ¹³ C NMR (100 MHz, CD ₂ CI ₂ , 25 °C, TMS): δ = 186.4, 184.5, 147.4, 140.2, 138.8, 138.5, 137.6, 137.5, 128.1 , 126,4, 123.4, 123.2, 121.6, 102.4, 27.9, 26.8, 22.8, 20.9. Anal. Calcd (%) for C ₃₄ H ₃₅ BFN0 ₂ Pt: C, 57.15; H, 4.94; N, 1.96. Found: C, 56.97; H, 4.95; N, 1.87. This product was also obtained when Pt(phenyl) ₂ (DMSO) ₂ was used in place of [PtMe ₂ (SMe ₂ )] ₂ .

Example 6: Synthesis of boron-functionalized C ^A C-chelate carbene complexes BC1 and BC2 p: 1 c, 38% p: 1 d, 80% p: BC1 , 25% m: 2c, 73% m: 2d, 70% m: BC2, 17%

Scheme for Example 6. Synthesis of boron-functionalized C ^A C-chelate carbene complexes. Reagents and conditions: i) n-BuLi, THF, -78°C; ii) FBMes ₂ , THF, -78°C to RT; iii) Pd/C, TsOH, EtOH, 25°C; iv) glyoxal THF/MeOH, 25°C; v) H ₂ CO, NH ₄ CI, 25°C; vi) H ₃ P0 ₄ , reflux; vii) NaOH(aq), 0°C; viii) Mel, THF, 25°C; ix) [PtMe ₂ (SMe ₂ )]2, -78°C to 55°C; x) TsOH, 25°C; xi) Na(acac), THF/MeOH, -78°C. /V,/V-dibenzyl-4-(dimesitylboryl)aniline (1a): To a 250 mL Schlenk flask was added A/,/v-dibenzyl-4-bromoaniline (1 .8 g, 5.1 mmol) and 80 mL dry THF. The resulting mixture was cooled to -78°C, then n-BuLi (3.5 mL, 5.6 mmol, 1 .6 M in hexanes) was added dropwise with stirring. The reaction was stirred for 1 h at -78°C, and then FBMes ₂ (1 .6 g, 6.1 mmol) was added. The reaction mixture was stirred at -78°C for 1 h, then allowed to warm slowly to room temperature and stirred for 16 h. After removal of the solvent in vacuo, the mixture was washed with saturated aqueous NH ₄ CI, then extracted with CH ₂ CI ₂ and water. The combined organic layers were dried using MgS0 ₄ , filtered, and purified using flash chromatography on silica gel (4:1 hexanes:CH ₂ CI ₂ as eluent) to afford 2.4 g 1a as a white solid (90% yield). ¹ H NMR (400 MHz, CDCI ₃ ) δ 7.43 (d, J = 8.2 Hz, 2H, -C ₆ H ₄ -), 7.35 (t, J = 7.1 Hz, 4H, -Ph), 7.32-7.22 (m, 6H, -Ph), 6.83 (s, 4H, Mes), 6.73 (d, J = 8.2 Hz, 2H, -C ₆ H ₄ -), 4.72 (s, 4H, -CH ₂ -), 2.32 (s, 6H, Mes), 2.12 (s, 12H, Mes) ppm; ¹³ C { ¹ H} NMR (100 MHz, CDCI ₃ ) δ 152.5, 142.1 , 140.6, 140.0, 137.8, 137.5, 133.0, 128.7, 127.9, 127.1 , 126.7, 1 1 1.2, 53.8, 23.5, 21.1 ppm; HRMS (High Resolution Mass Spectrometry) calc'd for C ₃₈ H ₄ oBN: 521.3254, found 321.3246. 4-dimesitylborylaniline (1b): To a 500 mL round-bottomed flask equipped with a magnetic stir bar was added 1a (2.37 g, 4.5 mmol), palladium on carbon (0.50 g, 5 wt% Pd), p-toluenesulfonic acid (0.50 g, 2.9 mmol) and ethanol (200 mL). The reaction was bubbled with hydrogen gas for 16 h at room temperature, then passed through a pad of celite and concentrated in vacuo. The residue was washed with 1 M aq. NaOH, then extracted with CH ₂ CI ₂ and water. The combined organic layers were dried using MgS0 , filtered, and purified using flash chromatography on silica gel (1 :1 hexanes:CH ₂ CI ₂ as eluent) to afford 1 .31 g 1b as a white solid (85% yield). ¹ H NMR (300 MHz, CDCI ₃ ) δ 7.39 (d, J = 8.4 Hz, 2H, -C ₆ H ₄ -), 6.82 (s, 4H, Mes), 6.61 (d, J = 8.4 Hz, 2H, -C ₆ H ₄ -), 4.03 (s, br, 2H, -NH ₂ ), 2.32 (s, 6H, Mes), 2.07 (s, 12H, Mes) ppm; ¹³ C { ¹ H} NMR (75 MHz, CDCI ₃ ) δ 150.5, 141.9, 140.7, 139.9, 137.7, 135.1 , 128.0, 1 13.8, 23.4, 21.1 ppm; HRMS calc'd for C ₂₄ H ₂₈ BN: 341.2315, found 341.2309.

A -(4-dimesitylborylphenyl)imidazole (1c): To a 100 mL round-bottomed flask with stir bar was added 1b (1.12 g, 3.3 mmol), glyoxal (0.375 mL, 40 wt.%, 3.28 mmol) and 10 mL 1 :1 THF:MeOH. The reaction was stirred for 16 h at room temperature, then NH ₄ CI (0.35 g, 6.6 mmol), formaldehyde (0.45 mL, 37 wt.%, 6.6 mmol) and 25 mL MeOH were added. The reaction was heated to reflux for 1 h, then 0.5 mL 85% H ₃ P0 ₄ was added. The mixture was heated to reflux for an additional 8h, then poured over ice (25 g), washed with 2M aq. NaOH, and extracted with CH ₂ CI ₂ and water. The combined organic layers were dried using MgS0 ₄ , filtered, and purified using flash chromatography on silica gel (4:1 ethyl acetate.hexanes as eluent) to afford 488 mg 1c as a white solid (38% yield). ¹ H NMR (400 MHz, CDCI ₃ ) <5 7.94 (s, br, 1 H, -Im), 7.63 (d, J = 8.2 Hz, 2H, -C ₆ H ₄ -), 7.37 (d, J = 8.2 Hz, 2H, -C ₆ H ₄ -), 7.35 (s, br, 1 H, -Im), 7.21 (s, br, 1 H, -Im), 6.84 (s, 4H, Mes), 2.31 (s, 6H, Mes), 2.02 (s, 12H, Mes) ppm; ¹³ C { ¹ H} NMR (100 MHz, CDCI ₃ ) δ 144.8, 141.3, 140.7, 139.8, 139.0, 138.1 , 135.4, 130.7, 128.3, 120.1 , 1 17.7, 23.4, 21.2 ppm; HRMS calc'd for C ₂₇ H ₂₉ BN ₂ : 392.2424, found 392.2429.

/V-(4-dimesitylborylphenyl)-A '-methylimidazolium iodide (1d): To a 25 mL round-bottomed flask with stir bar was added 1c (400 mg, 1.01 mmol), methyl iodide (0.32 mL, 5.1 mmol) and 10 mL THF. After stirring at room temperature for 40 h under air, the white precipitate was filtered, washed with THF and dried to afford 433 mg 1d (80% yield). ¹ H NMR (300 MHz, MeOH-d ₄ ) δ 9.59 (s, 1 H, Im), 8.15 (d, J = 2.1 Hz, 1 H, Im), 7.81 (d, J = 2.1 Hz, 1 H, Im), 7.76 (d, J = 8.6 Hz, 2H, -C ₆ H ₄ -), 7.69 (d, J = 8.6 Hz, 2H, -C ₆ H ₄ -), 6.86 (s, 4H, Mes), 4.06 (s, 3H, -CH ₃ ), 2.30 (s, 6H, Mes), 1.99 (s, 12H, Mes) ppm; Anal. Calc'd for C ₂₈ H ₃₃ BIN ₂ : C 62.83, H 6.21 , N 5.23, found C 62.82, H 5.99, N 5.12.

A/,/V-dibenzyl-3-(dimesitylboryl)aniline (2a): Prepared in analogy with 1a (83% yield). ¹ H NMR (400 MHz, CDCI ₃ ) δ 7.37 (t, J = 7.4 Hz, 1 H, -C ₆ H ₄ -), 7.34-7.25 (m, 7H, -Ph, -C ₆ H ₄ -), 7.21 -7.15 (m, 5H, -Ph, -C ₆ H ₄ -), 6.92 (s, 1 H, -C ₆ H ₄ -), 6.77 (s, 4H, Mes), 4.59 (s, 4H, -CH ₂ -), 2.33 (s, 6H, Mes), 1.99 (s, 12H, Mes) ¹³ C { ¹ H} NMR (100 MHz, CDCI ₃ ) δ 148.4, 146.4, 141.9, 140.6, 138.8, 138.0, 128.6, 128.5, 128.0, 126.9, 125.2, 121.0, 1 16.8, 1 12.5, 55.0, 23.2, 21.2 ppm; HRMS calc'd for C ₃₈ H ₄₀ BN: 521.3254, found 521.3260.

3-dimesitylborylaniline (2b): Prepared in analogy with 1 b (81 % yield). ¹ H NMR (400 MHz, CDCI ₃ ) 5 7.15 (t, J = 7.5 Hz, 1 H, -C ₆ H ₄ -), 6.94 (d, J = 7.2 Hz, 1 H, -C ₆ H ₄ -), 6.86-6.78 (m, 6H, -C ₆ H ₄ -, Mes), 3.52 (s, br, 2H, -NH ₂ ), 2.32 (s, 6H, Mes), 2.04 (s, 12H, Mes) ppm; ¹³ C { ¹ H} NMR (100 MHz, CDCI ₃ ) δ 147.2, 145.9, 141.9, 140.8, 138.5, 128.8, 128.1 , 126.8, 122.1 , 1 18.7, 23.3, 21.2 ppm; HRMS calc'd for C ₂₄ H ₂₈ BN: 341.2315, found 341.2319. A/-(3-dimesitylborylphenyl)imidazole (2c): Prepared in analogy with 1c (73% yield). ¹ H NMR (400 MHz, CDCI ₃ ) δ 7.76 (s, br, 1 H, -Im), 7.52-7.42 (m, 4H, -C ₆ H ₄ -), 7.21 (s, br, 1 H, -Im), 7.15 (s, br, 1 H, -Im), 6.83 (s, 4H, Mes), 2.31 (s, 6H, Mes), 2.00 (s, 12H, Mes) ppm; ³ C { ¹ H} NMR (75 MHz, CDCI ₃ ) δ 148.2, 141.1 , 140.8, 139.3, 137.2, 135.6, 135.1 , 130.1 , 129.5, 128.4, 128.2, 124.6, 1 18.4, 23.4, 21.2 ppm; HRMS calc'd for C ₂₇ H ₂₉ BN ₂ : 392.2424, found 392.2411. V-(3-dimesitylborylphenyl)-/V-methylimidazolium iodide (2d): Prepared in analogy with 7.1 (70% yield). ¹ H NMR (400 MHz, MeOH-d ₄ ) 69.43 (s, 1 H, Im), 7.98 (d, J = 2.1 Hz, 1 H, Im), 7.87 (dt, J = 7.6 Hz, J = 1.7 Hz, 1 H, -C ₆ H ₄ -), 7.74 (d, J = 2.1 Hz, 1 H, Im), 7.68 (t, J = 7.7 Hz, 1 H, -C ₆ H ₄ -), 7.66 (d, J = 1.7 Hz, 1 H, -C ₆ H ₄ -), 7.65 (d, J = 7.9 Hz, 1 H, -C ₆ H ₄ -), 6.86 (s, 4H, Mes), 4.00 (s, 3H, -CH ₃ ), 2.29 (s, 6H, Mes), 1 .99 (s, 12H, Mes) ppm; ¹³ C { ¹ H} NMR (100 MHz, MeOH-d ₄ ) δ 150.5, 142.4, 142.2, 141.2, 138.5, 137.2, 136.7, 131.7, 129.7, 129.6, 126.9, 125.9, 123.0, 37.1 , 23.9, 21.5 ppm; Anal. Calc'd for C ₂₈ H ₃₃ BIN ₂ : C 62.83, H 6.21 , N 5.23, found C 62.92, H 6.53, N 4.58. As shown in Scheme for Example 6 above, compounds 1d and 2d were reacted using the general synthesis provided herein to form their Pt complexes BC1 and BC2 with the addition of cooling to the indicated temperatures. An analogous reaction with sodium nacnac in place of sodium acac would form Pt(B-NHC1 )(nacnac) and Pt(B-NHC2)(nacnac).

Example 7. The following schematic shows a synthetic pathway for an organoboron ligand that comprises a BMes ₂ functionalized phenyl ring and a triazole ring

3a

Scheme for Example 7. Synthetic pathway for an organoboron ligand that comprises a BMes ₂ functionalized phenyl ring and a triazole ring. Reagents and conditions: i) n-BuLi, -78 °C, Et ₂ 0, 1 h; ii) B es ₂ F, RT, overnight; iii) TMS acetylene, Pd(PPh ₃ ) ₄ , Cul, Et ₃ N, 80°C, overnight; iv) NaOH, THF/MeOH, RT, 2h; v) RN ₃ , Cu(CH ₃ CN) ₄ PF ₆ , DIPEA, TBTA, DCM, RT.

Example 7A. Synthesis of (4-bromophenyl)dimesitylborane see steps (i) and (ii) of Scheme for Example 7: To a 100 mL Schlenk flask equipped with a magnetic stir bar was added para-dibromobenzene (1.0 g, 4.24mmol) and 30 mL of dry diethyl ether (Et ₂ 0). The resulting solution was cooled to -78°C and stirred for 30 minutes. At that time, 2.9 mL of 1.6 M n-butyllithium (n-BuLi) (4.64mmol) was slowly added. The mixture was maintained at -78°C for 1 h, and dimesitylboron fluoride (1.36g, 5.07mmol) was added. The resulting mixture was stirred at -78°C for another hour. It was then slowly warmed to room temperature (RT) and stirred overnight. The following morning, the solvent was removed under reduced pressure. A crude product was dissolved using dichloromethane solvent. The hydrophobic solvent solution was washed with brine and water. The combined hydrophobic phase was dried over MgS0 ₄ and filtered through filter paper. The product was further purified using flash chromatography through silica using hexane as eluent to afford 1.2 g of (4-bromophenyl)dimesitylborane, as a white solid (70% yield). Notably, the above synthetic procedure could also be used to synthesize (3-bromophenyl)dimesitylborane when meia-dibromobenzene is used in place of para-dibromobenzene. Also,

(2-bromophenyl)dimesitylborane can be synthesized when ο/ΐΛο-dibromobenzene is used in place of para-dibromobenzene. Example 7B. Synthesis of (4-ethynylphenyl)dimesitylborane see steps (iii) and (iv) of Scheme for Example 7: A 100 mL three-necked round bottomed flask, equipped with a magnetic stir bar and condenser, was charged with ligand (4-bromophenyl)dimesitylborane (1.22 g, 3.03mmol), trimethylsilylacetylene (0.45ml_, 3.44mmol),

tetrakis(triphenylphosphine)palladium(0) (0.175g, 0.15mmol), copper iodide (0.03g,

0.15mmol) and 30 mL of degassed triethylamine. The mixture was stirred at 80°C for 20 hours, and then concentrated under reduced pressure. The product was dissolved in dichloromethane solvent. The hydrophobic solvent solution was then sequentially washed with saturated ammonium chloride solution, brine and water. The combined hydrophobic phase was dried over MgS0 ₄ and filtered through a filter paper. The product was then purified using flash chromatography through silica using hexane as eluent. After removal of eluent solvent under reduced pressure, the resulting white solid was dissolved in 10 mL of tetrahydrofuran solvent and treated with sodium hydroxide in methanol (20 mL of a 2.0 M solution). After stirring for 2 hour, the resulting mixture was concentrated under reduced pressure. After extraction with dichloromethane, the hydrophobic solution was dried over MgS0 , filtered and the solvent was removed under reduced pressure to give the product (4-ethynylphenyl)dimesitylborane as a white solid (0.67g, 65%).

Notably, the above synthetic procedure could also be used to synthesize

(2-ethynylphenyl)dimesitylborane or 3-ethynylphenyl)dimesitylborane when 2- and 3- -bromophenyl)dimesitylborane are used instead of (4-bromophenyl)dimesitylborane, respectively.

Example 7C. Synthesis of 4-(4-(dimesitylboryl)phenyl)-1-benzyl-1 ,2,3-triazole (3a) see step (v) of Scheme for Example 7: To a 50 mL Schlenk flask equipped with a magnetic stir bar was added (4-ethynylphenyl)dimesitylborane (0.64g, 1.84mmol), benzyl azide (0.245g, 1.84mmol), diisopropylethylamine (0.475g, 3.68mmol),

tris[(1-benzyl-1 -/-1 ,2,3-triazol-4-yl)methyl]amine (1 mol %) and 30 mL of dichloromethane. The resulting solution was bubbled with nitrogen gas for 20 minutes. [Cu(CH ₃ CN) ₄ ]PF ₆ (1 mol %) was added as a catalyst. The resulting mixture was stirred overnight, after which the solvent was removed under reduced pressure. The crude product was dissolved in dichloromethane. The solution was washed with saturated ammonium chloride solution, brine and water. Following isolation, the non-aqueous phase was dried over MgS0 ₄ and filtered through a filter paper. The product was then purified using flash chromatography through silica (4:1 hexanes:ethyl acetate as eluent) to afford 0.64 g

4-(4-(dimesitylboryl)phenyl)-1-benzyl-1 ,2,3-triazole (3a) as white solid (72% yield).

Notably, the above synthetic procedure could also be used to synthesize

4-(3-(dimesitylboryl)phenyl)-1-benzyl-1 H-1 ,2,3-triazole when

(3-ethynylphenyl)dimesitylborane is used instead of (4-ethynylphenyl)dimesitylborane.

Example 8. Synthesis of Platinum complexes having a cyclometalation ligand and a stabilizing ligand

Scheme for Example 8. Synthesis of Platinum complexes having a cyclometalation ligand and a stabilizing ligand. Reagents and conditions:!) [PtMe ₂ (i/-SMe ₂ )]2, acetone, 80°C, 2-3h; ii) p-toluenesulfonic acid, THF, 1 h; iii) Na(acac), MeOH, overnight; iv) picolinic acid, MeOH, overnight.

Example 8A. Synthesis of Pt(4-(4-B es ₂ -phenyl)-1-benzyl-1,2,3-triazolyl)(acac) (C5), see Scheme for Example 8: BMes ₂ -functionalized phenyl-triazole (3a) ligand (0.10 mmol) and [PtMe ₂ (u-SMe ₂ )]2 (0.032 g, 0.055 mmol) were added to a 20 mL screw-cap vial with of acetone (5 ml_). The resulting mixture was heated to and maintained at 75 °C for 2 hours. Then, a 0.10 M solution of TsOH in THF (1 mL) was added. The resulting solution was stirred for 1 hour. Next, 0.1 M solution of Na(acetylacetonate) in methanol (2 mL) was added and the mixture was stirred overnight. The solvent was then removed under reduced pressure. The crude product was dissolved in dichloromethane and washed with with brine and water. The combined non-aqueous phase was dried over MgS0 ₄ and filtered through a filter paper. The product was purified through silica using dichloromethane as the eluent to to afford 0.0195g C5 as yellow solid (24% yield). ¹ H NMR (400 MHz, CD ₂ CI ₂ ):67.51 (s, 1 H), 7.47 (s, 1 H), 7.40-7.28 (m, 5H), 7.1 1 (d, ³ J=7.6Hz, 1 H), 7.07 (d, ³ J=7.6Hz, 1 H), 6.74 (s, 4H), 5.49 (s, 2H), 5.37 (s,1 H), 2.20 (s, 6H), 1.97 (s, 12H), 1.88 (s, 3H), 1.60 (s, 3H) ppm; elemental analysis calcd (%) for C ₃₈ H4oBN ₃ 0 ₂ Pt: C 58.77, H 5.19, N 5.41 , found: C 58.76, H 5.21 , N 5.39.

Example 8B. Synthesis of Pt-(4-(4-B es ₂ -phenyl)-1-benzyl-1 ,2,3-triazolyl)(picolinate)

(C10): Ligand 3a (0.05g, O.I Ommol) and [PtMe ₂ (u-SMe ₂ )] ₂ (0.032g, 0.055mmol) were added to a 20mL screw-cap vial with 5mL of acetone. The mixture was heated at 75°C for 2 hours before 2mL of 0. 0 M solution of picolinic acid in methanol was added. The resulting solution was stirred overnight. After the solvent was removed under reduced pressure, the product was extracted with dichloromethane, and then washed with brine and water. The combined organic phase was dried over MgS0 ₄ , filtered and purified on silica (2:1 dichloromethane:ethyl acetate as eluent) to afford 0.021 g of C10 as yellow solid (26% yield). ¹ H NMR (500 MHz,

CD ₂ CI ₂ ):69.52 (d, ³ J=5.6Hz, 1 H), 8.14 (m, 1 H), 7.80 (s, 1 H), 7.70 (m, 1 H), 7.62 (s, 1 H),

7.50-7.42 (m, 5H), 7.27 (d, ³ J=7.5Hz, 1 H), 7.16 (d, ³ J=7.5Hz, 1 H), 6.88 (s, 4H), 5.64 (s, 2H), 2.34 (s, 6H), 2.06 (s, 12H); elemental analysis calcd (%) for C ₃₉ H ₃₇ BN ₄ 0 ₂ Pt: C 58.58, H 4.68, N 7.01 , found: C 59.83, H 5.18, N 6.44. Example 8C. Synthesis of C11

A BMes2-functionalized phenyl-triazole ligand (O.I Ommol) and [PtMe2(u-SMe2)]2 (0.032g, 0.055mmol) were added to a 20mL screw-cap vial with acetone (5mL). The resulting mixture was heated to and maintained at 75oC for 2 hours. Then, 0.1 M solution of the

1 ,5-dimethyl-1 H-pyrazole-3-carboxylic acid in methanol (2mL) was added. The resulting solution was stirred overnight. A precipitated solid was collected on a filter paper and washed with methanol, hexane and acetone (3 χ 5 mL each) and dried in air.

Example 8D. Synthesis of C12

A BMes2-functionalized phenyl-triazole (3a) ligand (0.10 mmol) and [PtMe2(u-SMe2)]2 (0.032 g, 0.055 mmol) were added to a 20 mL screw-cap vial with of acetone (5 mL). The resulting mixture was heated to and maintained at 75 °C for 2 hours. Then, a 0.10 M solution of TsOH in THF (1 mL) was added. The resulting solution was stirred for 1 hour. Next, 0.1 M solution of 2-(1 H-1 ,2,4-triazol-3-yl)pyridine in methanol (2 mL) was added and the mixture was stirred overnight. The solvent was then removed under reduced pressure. The crude product was dissolved in methanol and purified on TLC plate using acetone as the eluent.

Example 8E. Synthesis of Pt(BMes ₂ -triazolyl)(picolinate)

See C6-C1 1 of the above Scheme for Example 8: The BMes ₂ -functionalized phenyl-triazole ligand (O.I Ommol) and [PtMe ₂ (u-SMe ₂ )] ₂ (0.032g, 0.055mmol) were added to a 20mL screw-cap vial with acetone (5mL). The resulting mixture was heated to and maintained at 75°C for 2 hours. Then, 0.1 solution of the corresponding picolinic acid or substituted picolinic acid in methanol (2mL) was added. The resulting solution was stirred overnight. A precipitated solid was collected on a filter paper and washed with methanol, hexane and acetone (3 ^χ 5 mL each) and dried in air.

Example 8F. Synthesis of 2-(3-bromo-phenyl)-benzimidazole (see first step of Scheme for Example 8F)

Scheme for Example 8F. Synthesis of 2-(3-bromo-phenyl)-benzimidazole 3-bromobenzoic acid (2.0g, 9.9 mmol) was added to the solution of

1 ,2-phenylenediamine (1.07 g, 9.9 mmol) in polyphsphoric acid (PPA) (40 ml.) at 120 °C. The resulting solution was heated to and maintained at 150 °C and stirred for 3 hrs. Upon cooling of the solution, it was poured into water. A resulting precipitate was filtered off. 10% NaOH aqueous solution was added to the filtrate until the pH was 10. In this process, a large quantity of precipitate was produced, which was then filtrated off using a filter paper. This filtrate was extracted with diethyl ether 3 times. 2-(3-bromo-phenyl)-benzimidazole was obtained as a white solid after the solvent was removed under reduced pressure (yield, 55%). ¹ H NMR (ppm, 300 M in d ⁶ -DMSO): 13.03 (1 H, s), 8.37 (1 H, s), 8.18 (1 H, d, J = 8.18 Hz), 7.70 (2H, m), 7.53 (2H, m), 7.25 (2H, m).

Example 8G. Synthesis of N-Me-2-(3-bromo-phenyl)-benzimidazole (see second step of Scheme for Example 8F)

K-Ot-Bu (0.23 g, 0.2 mmol) was added to a stirred solution of

2-(3-bromo-phenyl)-benzimidazole (0.45 g, 0.2 mmol) in THF for 20 min. Excess methyl iodide was added to the solution, which was then stirred overnight. After filtering off the precipitate and removal of the solvent under reduced pressure,

N-Me-2-(3-bromo-phenyl)-benzimidazole was obtained quantitatively. ¹ H NMR (ppm, 300 M in CDCI ₃ ): 7.97 (1 H, s), 7.84 (1 H, m), 7.69 (1 H, d, J = 7.5 Hz), 7.64 (1 H, J = 8.1 Hz), 7.38 (4H, m), 3.87 (3H, m).

Example 8H. Synthesis of N-Me-2-(3-BMes ₂ -phenyl)-benzimidazole (see imidazole 1 in Scheme for Example 8F)

n-BuLi (0,8 mL, 1.3 mmol) was added slowly to a solution of

N-Me-2-(3-bromo-phenyl)-benzimidazole (0.29 g, 1.0 mmol) in THF (30 mL) at -78 °C and the resulting solution was stirred for about 1 hour at -78 °C. BMes ₂ F (0.37 g, 1.4 mmol) was then added under a stream of nitrogen and the solution was stirred at the same temperature for about 2 hours and then stirred overnight at ambient temperature. The solvents were removed under reduced pressure. The residue was purified over silica gel by flash column

chromatography using a CH ₂ CI ₂ /hexanes (1 :1 ) mixture give a white powder of

N-Me-2-(3-BMes ₂ -phenyl)-benzimidazole ("imidazole 1 ") (0.23 g, 50%). ¹ H NMR (400 MHz, CDCI ₃ , ppm): 8.08 (1 H, broad), 7.90 (1 H, b), 7.76 (1 H, s), 7.73 (1 H, m), 7.62 (1 H, m), 7.41 (3H, b), 6.85 (4H, s), 3.78 (3H, s), 2.33 (3H, s), 2.05 (12H, s).

Example 8I. Synthesis of Pt complexes Pt-12 as shown in Scheme for Example 8F

Pt complexs Pt-12 were synthesized using procedures similar to that reported in the literature procedure (Z. M. Hudson et al., Org. Lett. 2012, 14, 1700-1703). 1 eq of ligand imidazole 1 (1 mmol) and 1 equivalent PtMe ₂ (SMe ₂ ) ₂ (1 mmol) were combined and stirred at RT in 3mL THF for 2hrs. 1 equivalent of p-tolunenesulfonic acid was added to the solution and stirred for another 0.5 h, which was then followed by the addition of 2 equivalents of Na(acac) in 2 mL MeOH. The mixture was stirred for 2 hrs. The solvent was then removed under vacuum and the residue was purified using column chromatograph on silica

(dichlormethane /hexane: 1/1 v), producing Pt-12 in good yield. ¹ H NMR (400 MHz, CD ₂ CI ₂ , ppm): 8.84 (1 H, m), 7.77 (2H, m), 7.39 (3H, m), 7.32 (1 H, dd, J = 8.0 Hz, J = 1.2 Hz), 6.89 (4H, s), 5.06 (1 H, s), 2.35 (6H, s), 2.12 (12H, s), 2.1 1 (3H, s), 2.02 (3H, s). ¹³ C NMR (125.6 MHz, CD ₂ CI ₂ , ppm): 185.4, 183.6, 141.7, 140.6, 138.3, 138.1 , 132.4, 130.6, 128.0, 124.0, 123.0, 1 16.4, 109.6, 101.9, 31.2, 27.6, 27.0, 23.3, 21.0. Absorption and emission spectra are shown for Pt-12 in Fig. 30 and 31. The solution luminescence quantum efficiency of Pt-12 compared to that of lr(ppy) ₃ is 0.5. Compounds 51 and 52 are synthesized in a similar way to the synthesis of Pt-12, by replacing Na(acac) with Na(nacnac) in the reaction.

Syntheses of Pt complexes with nacnac as a stabilizing ligand are procedurally the same as the corresponding acac complex, except that sodium nacnac would be used instead of sodium acac. A person with skill in the art of the invention would recognize that this ligand with another counterion would be equivalent (e.g., potassium nacnac).

Example 8J. Synth ^A C chelate Pt(ll) -diketonate complex

10

Scheme for Example 8J. Synthesis of a P ^A C chelate Pt(ll) /3-diketonate complex

To a 20 mL screw-cap vial equipped with a magnetic stir bar was added

1 -naphthyldiphenylphosphine (97 mg, 0.35 mmol), [PtMe ₂ (SMe ₂ )] ₂ dimer (100 mg, 0.17 mmol) and 3 mL degassed THF. The resulting reaction mixture was stirred for 4 hours at 55°C under an N ₂ atmosphere. Then, HOTf (1 mL, 0.35 M in THF) was added dropwise. The mixture was stirred for 30 minutes at room temperature. A solution of Na(acac) ^« H ₂ 0 (98 mg, 0.70 mmol in 2 mL MeOH) was then added. The mixture was stirred for 1.5 hours. The reaction mixture was then partitioned between water and CH ₂ CI ₂ . The hydrophobic layer was washed with brine, dried over MgS0 ₄ , filtered, and concentrated under reduced pressure. The residue was then purified using a plug of silica gel (hexanes and CH ₂ CI ₂ as eluent) to give 10 as a white solid in 65% yield.

10: ¹ H NMR (400 MHz, Chloroform-d) δ 8.24 (d, sat, J _Pt . _H = 44.6 Hz, J = 7.1 Hz, H), 7.91-7.80 (m, 5H), 7.67 (dd, J = 10.5 Hz, 7.1 Hz, 1 H), 7.58 (dd, J = 8.1 , 1.8 Hz, 1 H), 7.51-7.36 (m, 8H), 5.52 (s, 1 H), 2.16 (s, 3H), 1.93 (s, 3H) ppm; ¹³ C MR (100 MHz, Chloroform-d) δ 186.10, 184.8 (d, Jp. _c = 3.7 Hz), 151.3 (d, J _P-C = 30.4 Hz), 134.12 (d, J _P-C = 52.7 Hz), 133.81 (d, d, Jp. _c = 16.8 Hz), 133.24 (d, d, J _P . _C = 15.0 Hz), 132.93 (d, J _P-C = 1 1.7 Hz), 130.9 (d, J _P-C = 62.9 Hz), 131.1 (d, J _P-C = 2.6 Hz), 130.7 (d, J _P-C = 32.2 Hz), 128.8 (d, J _P . _C = 1.8 Hz), 128.5, 128.4, 126.5, 125.0 (d, J _P-C = 10.3 Hz), 122.7, 101.6, 28.2, 28.1 (d, J _P . _C = 6.6 Hz) ppm; ³¹ P NMR (169 MHz, Chloroform-d) δ 28.27 (s, sat, J _Pt-P = 4671 Hz) ppm; Anal, calc'd for C ₂₇ C ₂₃ 0 ₂ PPt: C 53.55, H 3.83, found C 53.59, H 3.70; m.p. 222-223 °C. Example 8K. Synthesis of 11 , a C ^A C chelate Pt(ll) /3-diketonate complex

11

Scheme for Example 8K. Synthesis of a C ^A C chelate Pt(ll) 3-diketonate complex.

To a 20 mL screw-cap vial with stir bar was added 1 -methyl-3-phenylimidazol-2- ylidine)silver chloride (100 mg, 0.35 mmol), [PtMe ₂ (SMe ₂ )]2 dimer (100 mg, 0.17 mmol) and 3 mL degassed THF. The reaction was stirred for 1 hour, and then was filtered to remove Agl. The resulting mixture was then heated to and maintained at 55°C for two hours, and then was cooled to room temperature. HOTs (1 mL, 0.35 M in THF) was then added dropwise, and the mixture was stirred for 30 minutes at room temperature. After cooling the reaction to -40°C, a solution of Na(acac) ^« H ₂ 0 (49 mg, 0.35 mmol in 1 mL MeOH) was added dropwise. The mixture was stirred for 2 hours, and then was allowed to warm to room temperature. After partitioning between water and CH ₂ CI ₂ , the hydrophobic layer was washed with brine, and the combined extracts were dried over MgS0 ₄ . The solution was filtered and concentrated under reduced pressure. The resulting residue was purified using a plug of silica gel, with CH ₂ CI ₂ as eluent, to give 11 as a yellow solid in 61 % yield.

11 : ¹ H NMR (400 MHz, Chloroform-d) δ 7.78 (dd, sat, J _Pt-H = 52.1 Hz, J = 5.3, 2.0 Hz, 1 H), 7.24 (d, J = 2.0 Hz, 1 H), 7.01 (m, 2H), 6.93 (dd, J = 6.8, 2.0 Hz, 1 H), 6.80 (d, J = 2.0 Hz, 1 H), 5.49 (s, 1 H), 4.07 (s, 3H), 2.05 (s, 3H), 1.96 (s, 3H) ppm; Anal, calc'd for C ₁₅ H ₁₆ N ₂ 0 ₂ Pt: C 39.91 , H 3.57, N 6.21 , found C 40.34, H 3.60, N 6.08 (Zachary M. Hudson et al., Org. Lett. 2012, 14: 1700-1703).

Example 8L. Synthesis of Pt(ll) compounds Pt-8, Pt-9, Pt-110, and Pt-111

Ancillary ligands f-Bu-pytrz-Me and CF ₃ - pytrz-Me were synthesized according to literature procedure (E. Orselli, G. S. Kottas, A. E. Konradsson, P. Coppo, R. Frohlich, L. D. Cola, A. V. Dijken, M. Buchel, H. Borner, Inorg. Chem., 2007, 46, 1 1082). The Bptrz ligand (0.10 mmol) and [PtMe ₂ (u-SMe ₂ )] ₂ (0.055 mmol) were added to a 20 mL screw-cap vial with 5 mL of acetone. The mixture was heated at 70 °C for 3 hours before 1 mL of 0.1 M solution of TsOH in acetone was added. The resulting solution was stirred for 1 hour, then 0.13 mmol of corresponding pytrz ligand in acetone was added and the mixture was stirred at RT for 3 days. The product was filtered and washed with hexane, diethyl ether and methanol, sequentially. The product was further purified via chromatography and recrystallization from CH ₂ CI ₂ or THF with hexane. Unless specified, compounds 8 - 11 refer to the N ^' '-trans isomers (X. Wang, Y,-L Chang, J. -S. Lu, T. Zhang, Z. H. Lu, S. Wang, Adv. Funct. Mater., 2013, Early view article on line, December 4 ^th , 2013 (DOI: 10.1002/adfm.201302871 ).

(m-LI )Pt(pytrz) (Pt-8): (23% yield). ¹ H N R (400 MHz, CD ₂ CI ₂ , δ, ppm): 9.76 (d, ³ J=6 Hz, 1 H), 9.12 (d, ³ J=7.6 Hz 1 H), 8.16-8.09 (m, 3H), 7.65 (s, 1 H), 7.50-7.40 (m, 7H), 7.33 (dd, ³ J=7.8 Hz, ⁴ J=1.5Hz, 1 H), 6.85 (s, 4H), 5.65 (s, 2H), 2.33 (s, 6H), 2.05 (s, 12H). Elemental analysis, calcd (%) for 8-0.5 CH ₂ CI ₂ C 56.23, H 4.54, N 1 1 .33, found: C 56.38, H 4.84, N 10.90.

(m-LI )Pt(f-Bu-pytrz-Me) (Pt-9): (27% yield). ¹ H NMR (400 MHz, CD ₂ CI ₂ , δ, ppm): 9.52 (d, ³ J=5.1 Hz, 1 H), 9.19 (d, ³ J=7.5 Hz 1 H), 7.94 (s, 1 H), 7.61 (s, 1 H), 7.50-7.40 (m, 6H), 7.30 (m, 2H), 6.85 (s, 4H), 5.62 (s, 2H), 2.54 (s, 3H), 2.33 (s, 6H), 2.05 (s, 12H), 1 .48 (s, 9H).

Elemental analysis, calcd (%) for C ₄₅ H ₄₈ BN ₇ Pt: C 60.54, H 5.42, N 10.98, found: C 60.64, H 5.45, N 10.87.

(m-L1 )Pt(CF ₃ -pytrz-Me) (Pt-110): (25% yield). ¹ H NMR (400 MHz, CD ₂ CI ₂ , δ, ppm):69.58 (d, ³ J=5.7 Hz, 1 H), 8.96 (d, ³ J=7.7 Hz 1 H), 8.02 (s, 1 H), 7.63 (s, 1 H), 7.50-7.40 (m, 7H), 7.32 (m, 1 H), 6.84 (s, 4H), 5.65 (s, 2H), 2.56 (s, 3H), 2.33 (s, 6H), 2.05 (s, 12H). Elemental analysis, calcd (%) for 10 CH ₂ CI ₂ (C ₄₃ H ₄₁ BN ₇ CI ₂ F ₃ Pt): C 52.48, H 4.20, N 0.01 , found: C 52.19, H 4.17, N 9.91.

(m-L2)Pt(CF ₃ -pytrz-Me) (Pt-111 ): (27% yield). ¹ H NMR (400 MHz, CD ₂ CI ₂ , δ, ppm): 9.57 (d, ³ J=5.6 Hz, 1 H), 8.96 (d, ³ J=7.6 Hz 1 H), 8.03 (s, 1 H), 7.87 (s, 1 H), 7.56 (s, 1 H), 7.44 (d, ³ J=6.1 Hz,1 H), 7.32 (dd, ³ J=7.8 Hz, ⁴ J=1.3 Hz, H), 6.88 (s, 4H), 2.57 (s, 3H), 2.36 (m, 15H), 2.08 (s, 12H), 1.89 (m, 6H). Elemental analysis, calcd (%) for 11 -THF (C ₄₉ H ₅₅ BN ₇ 0 ₁ F ₃ Pt): C 57.65, H 5.43, N 9.60, found: C 57.97, H 5.49, N 9.17. All scientific and patent publications cited herein are hereby incorporated in their entirety by reference.

Although this invention is described in detail with reference to embodiments thereof, these embodiments are offered to illustrate but not to limit the invention. It is possible to make other embodiments that employ the principles of the invention and that fall within its spirit and scope as defined by the claims appended hereto.

Table 1. Structural Formulae

Pt-(Ph ₃ CP -Bn) (H-trz) "T16"

Pt-(Ph ₃ CPh-Ph ₂ CH) (CF ₃ -trz) "T15"

Pt-(Ph ₃ CPh-P ₂ CH) (H-trz) "T17" Pt-(Ph3CPh-Bn) (CF3-trz)

"T18"

Pt-(B-NHC1 )(acac), BC1 ^d

Pt-(B-NHC2)(acac), BC2 ^d

Pt(B-triazole1)(3,5-py- 1,2,4-triazole), "C16"

Pt(B-triazole1 )(2-py-4-CF ₃ -pyrazole), "C19"

Pt(B-triazole1 )(2-py-imidazole), "C22"

Pt(B-Me-ppy)(acac) 22 ^b

Table 2A. Photophysical properties of Phenyl-triazolyl-Pt compounds

Table 2B. Photophysical data of Pt(ll) Compounds

DCM using lr(ppy) ₃ as a reference under nitrogen. Solid state quantum efficiency was measured using an integration sphere. All quantum yields are ± 10%. [c] Recorded in CH ₂ CI ₂ (~2.0 x 0 ^~5 M). Table 2C. Photophysical Properties of BC1 and BC2

^[a] Measured in degassed CH ₂ CI ₂ at 1x10 ^"5 M,

l ^l Doped into PMMA at 10 wt%.

^[cl Solution quantum efficiencies were measured in CH ₂ CI ₂ relative to lr(ppy) ₃ = 0.97. ⁷ Solid state quantum yields (QY) were measured using an integration sphere. All QYs are ± 10%. ^[dl In DMF relative to FeCp ₂ ^0/+ .

^[e] Measured by UV photoelectron spectroscopy. ^[fl Calculated from the HOMO level and the optical energy gap.

Table 2D. Photophysical properties of BMes ₂ -phenyl-triazolyl/imidazolyl-Pt compounds

Table 2E. Photophysical data of Pt(ll) Compounds

[a] For compounds Pt-8, Pt-9, Pt-110 and Pt-111 , the data are for the N -trans isomers, [b] Measured in Me-THF at 2 x 10 ^"5 M . [c] The solution quantum efficiency was determined in Me-THF using 9,10-diphenylanthracene as the reference under nitrogen. The solid state quantum efficiency was measured using an integration sphere. All quantum yields are ± 10%. [d] Recorded in Me-THF (-1.0 x 10 ^"5 M) Table 3A. Electroluminescent Device Data of BC1 and BC2

a The International Commission on Illumination (abbreviated CIE for its French name) is the international authority on light, illumination, color, and color spaces.

Table 3B. EL device data for Pt-9 and Pt-110

Device ^max Von L 10 100 1000 He Π.Ρ (x.y)

(nm) ^a

(V) ^b (cd/m ² , V) ^c cd/m cd/m ² cd/m ² (cd/A) ^e (lm/W) ^f

2

5% Pt-9 467 3.2 2879, 8.4 10.4 8.3 4.6 23.6 23.2 (0.19, 0.34)

10% Pt-9 468 3.0 3220, 8.6 14.4 15.6 6.5 36.7 33.9 (0.31 , 0.44)

2% Pt-110 456 3.2 865, 9.2 5.0 2.5 - 1 1.8 10.9 (0.32, 0.42)

5% Pt-110 563 3.2 1420, 8.0 9.3 7.3 2.1 24.7 22.9 (0.38, 0.48) aValue taken at I = 20 mA. "The applied voltage (V _on ) is defined as brightness of 1 cd/m ² . ^c The luminance (L) is the maximum value. ^d External quantum efficiency (EQE, r\ _ext ). ^e Current efficiency (η ₀ ) and power efficiency (η _ρ ) are the maximum values.