Description

Organic semiconducting materials can be used in electronic devices such as organic photovol- taic devices (OPVs), organic field-effect transistors (OFETs), organic light emitting diodes (OLEDs), and organic electrochromic devices (ECDs).

For efficient and long lasting performance of the electronic device, it is desirable that the organic semiconducting material shows a high chemical stability under ambient air and light conditions.

Furthermore, it is desirable that the organic semiconducting materials are compatible with liquid processing techniques such as spin coating as liquid processing techniques are convenient from the point of processability, and thus allow the production of low cost organic semiconducting material-based electronic devices. In addition, liquid processing techniques are also compat- ible with plastic substrates, and thus allow the production of light weight and mechanically flexible organic semiconducting material-based electronic devices.

Acenes, other fully-conjugated ring systems and nitrogen-containing analogues thereof have attracted considerable attention in the past years as semiconducting materials for use in elec- tronic devices.

The preparation and characterization of acenes such as pentacenes and hexacenes and their potential as semiconducting material is reviewed by Anthony, J. E. in Angew. Chem. 2008, 120, 460 to 492. Clar, E. Chem. Ber. 1942, 75B, 1330 already pointed out that as the length of acene increases, the stability as well as the solubility significantly decreases. Mondal, R.; Tonshoff, C; Khon, D.; Neckers, D.C. Bettinger, H .F.; J. Am. Chem. Soc. 2009, 131 , 14281 to 14289 showed that hexacene of the following formula

was found to be very unstable in solution.

Chase, D.T.; Fix, A.G.; Kang, S.J.; Rose, B.D.; Weber, CD.; Zhong, Y.; Zakharow, L.N.; Loner- gan, M.C.; Nuckolls, C; Haley, M.M.; J. Am. Chem. Soc. 2012, 134, 10349-10352 describe the following fully-conjugated ring-system

and the use thereof as semiconducting material for organic field effect transistors (OFETs).

Bunz, U.H.F.; Engelhart, J.U.; Lindner, B.D.; Schaffroth, M. Angew. Chem. 2013, 125, 3898- 3910 review nitrogen-containing acene derivatives. Miao, S.; Appleton, A.L.; Berger, N.; Barlow, S.; Marder, S.R.; Hardcastle, K.I.; Bunz, U.H.F. describe the following air-stable and soluble tetraazo substituted acene derivatives

It was the object of the present invention to provide nitrogen-containing fully-conjugated ring systems, which nitrogen-containing fully-conjugated ring systems are of high chemical stability, in particular under ambient temperature, air and light conditions, and are also soluble in organic solvents. In addition, the nitrogen-containing fully-conjugated ring systems should be suitable for use as semiconducting material in electronic devices, in particular in organic field-effect transistors (OFETs).

This object is solved by the compounds of claim 1 , the electronic device of claim 8 und the use of claim 10. The organic semiconducting materials of the present invention are compounds of formula

wherein

R ¹ and R ² are independently from each other selected from the group consisting of H, C1-30- alkyl, C2-3o-alkenyl, C2-3o-alkynyl, Cs-s-cycloalkyl, Cs-s-cycloalkenyl, 5 to 14 membered heterocycloalkyi, 5 to 14 membered heterocycloalkenyl, C6-i4-aryl and 5 to 14 membered heteroaryl, and R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are independently from each other selected from the group consisting of H, Ci-30-alkyl, C2-3o-alkenyl, C2-3o-alkynyl, Cs-s-cycloalkyl, Cs-s-cycloalkenyl, 5 to 14 membered heterocycloalkyi, 5 to 14 membered heterocycloalkenyl, C6-i ₄ -aryl, 5 to 14 membered heteroaryl, halogen, CN, -SCN, N0 ₂ , OH, O-Ci-30-alkyl, 0-C ₂ - ₃ o-alkenyl, 0-C ₂ - ₃ o-alkynyl, 0-C5-8-cycloalkyl, O-Cs-s-cycloalkenyl, 0-5 to 14 membered heterocycloalkyi, 0-5 to 14 mem- bered heterocycloalkenyl, 0-C6-i4-aryl, 0-5 to 14 membered heteroaryl, SH, S-Ci-30-alkyl,

S-C2-3o-alkenyl, S-C2-3o-alkynyl, S-Cs-s-cycloalkyl, S-Cs-s-cycloalkenyl, S-5 to 14 membered heterocycloalkyi, S-5 to 14 membered heterocycloalkenyl, S-C6-i4-aryl, S-5 to 14 membered heteroaryl, C(0)H, CO-Ci-3o-alkyl, CO-C ₂ - ₃ o-alkenyl, CO-C ₂ - ₃ o-alkynyl, CO-C ₅ - ₈ -cycloalkyl, CO-Cs-s- cycloalkenyl, CO-5 to 14 membered heterocycloalkyi, CO-5 to 14 membered heterocycloal- kenyl, CO-C ₆ -i ₄ -aryl, CO-5 to 14 membered heteroaryl, COOH, NH(Ci- ₃₀ -alkyl), N(Ci- ₃ o-alkyl) ₂ , CON H2, CONH(Ci- ₃₀ -alkyl), CON(Ci- ₃₀ -alkyl) ₂ , S0 ₂ OH, SO2N H2, SO ₂ -Ci- ₃₀ -alkyl and S0 ₂ -C ₆ -i ₄ - aryl, wherein

Ci-3o-alkyl, C2-3o-alkenyl and C2-3o-alkynyl, can be substituted with one to nine substituents independently selected from the group consisting of Cs-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyi, 5 to 10 membered heterocycloalkenyl, Ce-10-aryl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ; and one or more CH ₂ -groups, but not adjacent Ch -groups of Ci-30-alkyl, C2-3o-alkenyl and C2-3o-alkynyl, and not the Ch -group directly attached to the core of the compound of formula (1 ), can be replaced by O or S, and

Cs-s-cycloalkyl, Cs-s-cycloalkenyl, 5 to 14 membered heterocycloalkyi and 5 to 14 membered heterocycloalkenyl can be substituted with one to five substituents independently selected from the group consisting of Ci-20-alkyl, C2-2o-alkenyl, C2-2o-alkynyl, C6-io-aryl, 5 to 10 mem- bered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ,

Ce-14-aryl can be substituted with one to five substituents independently selected from the group consisting of Ci-20-alkyl, C2-2o-alkenyl, C2-2o-alkynyl, Cs-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, and 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ , 5 to 14 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci-20-alkyl, C2-2o-alkenyl, C2-2o-alkynyl, Cs-6-cycloalkyl, C5-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, Ce-io-aryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], halogen, CN and NO2, wherein

R ^a and R ^b are independently selected from the group consisting of H, Ci-20-alkyl,

C2-2o-alkenyl and C2-2o-alkynyl,

Ci-20-alkyl, C2-2o-alkenyl and C2-2o-alkynyl can be substituted with one to five substituents selected from the group consisting of phenyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ], N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , and,

C5-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, Ce-10-aryl and 5 to 10 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci-10-alkyl, C2- 10-alkenyl, C ₂ -io-alkynyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ], N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , wherein

R ^c and R ^d are independently selected from the group consisting of H, Ci-10-alkyl, C2-io-alkenyl and C2-io-alkynyl,

wherein

Ci-10-alkyl, C2-io-alkenyl and C2-io-alkynyl can be substituted with one to five substituents selected from the group consisting of halogen, CN and NO2.

Halogen can be F, CI, Br and I. Ci-10-alkyl, Ci-20-alkyl and Ci-30-alkyl can be branched or unbranched. Examples of Ci-10-alkyl are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, ferf-butyl, n-pentyl, neopentyl, isopentyl, n-(1 -ethyl)propyl, n-hexyl, n-heptyl, n-octyl, n-(2-ethyl)hexyl, n-nonyl and n-decyl. Ex- amples of Ci-20-alkyl are Ci-10-alkyl and n-undecyl, n-dodecyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl and n-icosyl (C20). Examples of Ci-30-alkyl are Ci-20-alkyl and n-docosyl (C22), n-tetracosyl (C24), n-hexacosyl (C26), n-octacosyl (C28) and n-triacontyl (C30).

C2-io-alkenyl, C2-2o-alkenyl and C2-3o-alkenyl can be branched or unbranched. Examples of Ci-20-alkenyl are vinyl, propenyl, c/ ^' s-2-butenyl, frans-2-butenyl, 3-butenyl, c/s-2-pentenyl, trans- 2-pentenyl, c/s-3-pentenyl, frans-3-pentenyl, 4-pentenyl, 2-methyl-3-butenyl, hexenyl, heptenyl, octenyl, nonenyl and docenyl. Examples of C2-2o-alkenyl are C2-io-alkenyl and linoleyl (Cis), lino- lenyl (Cis), oleyl (Cis), and arachidonyl (C20). Examples of C2-3o-alkenyl are C2-2o-alkenyl and erucyl (C22).

C2-io-alkynyl, C2-2o-alkynyl and C2-3o-alkenyl can be branched or unbranched. Examples of C2-10- alkynyl are ethynyl, 2-propynyl, 2-butynyl, 3-butynyl, pentynyl, hexynyl, heptynyl, octynyl, non- ynyl and decynyl. Examples of C2-2o-alkynyl and C2-3o-alkenyl are undecynyl, dodecynyl, un- decynyl, dodecynyl, tridecynyl, tetradecynyl, pentadecynyl, hexadecynyl, heptadecynyl, octade- cynyl, nonadecynyl and icosynyl (C20).

Examples of C6-io-aryl are phenyl, naphthyl, anthracenyl and phenantrenyl.

Examples of C6-i ₄ -aryl are C6-io-aryl and tetracenyl and chrysenyl.

Examples of Cs-s-cycloalkyl are cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl. Examples of C5-6-cycloalkyl are cyclopentyl and cyclohexyl. Examples of Cs-s-cycloalkenyl are cyclopentenyl, cyclohexenyl, cycloheptenyl and cyclooctenyl. Examples of Cs-6-cycloalkyl are cyclopentenyl and cyclohexenyl.

Examples of 5 to 10 membered heterocycloalkyl and 5 to 14 membered heterocycloalkyl are

101

wherein R ¹⁰¹ is at each occurrence Ci-6-alkyl or phenyl. Examples of 5 to 10 membered heterocycloalkenyl and 5 to 14 membered heterocycloalkenyl are

102

wherein R ¹⁰⁰ is at each occurrence Ci-6-alkyl or phenyl. Examples of 5 to 14 membered heteroaryl are the examples given for the 5 to 10 membered heteroaryl and

wherein R ¹⁰⁰ is at each occurrence Ci-6-alkyl or phenyl.

Preferred are compounds of formula

wherein R ¹ and R ² are independently from each other selected from the group consisting of H, C1-30- alkyl, Ce-14-aryl, and 5 to 14 membered heteroaryl, and

R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are independently from each other selected from the group consisting of H, Ci-30-alkyl, Ce-14-aryl, 5 to 14 membered heteroaryl, halogen, CN , -SCN , NO2, OH, 0-Ci-3o-alkyl, O-Ce-14-aryl, 0-5 to 14 membered heteroaryl, SH , S-Ci-30-alkyl, S-Ce-14-aryl, S-5 to 14 membered heteroaryl, C(0)H, CO-Ci-30-alkyl, CO-C ₆ -i4-aryl, CO-5 to 14 membered heteroaryl, COOH, NH(Ci- ₃₀ -alkyl), N(Ci- ₃₀ -alkyl) ₂ , CONH ₂ , CONH(Ci- ₃₀ -alkyl), CON(Ci- ₃₀ -alkyl) ₂ , SO2OH , SO2N H2, S0 ₂ -Ci-3o-alkyl and S0 ₂ -C ₆ -i4-aryl, wherein

Ci-3o-alkyl can be substituted with one to nine substituents independently selected from the group consisting of C ₆ -io-aryl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , N R ^a R ^b , N R ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ; and one or more Ch -groups, but not adjacent Ch -groups of Ci-30-alkyl and not the CH2-group directly attached to the core of the compound of formula (1 ), can be replaced by O or S, and

Ce-14-aryl can be substituted with one to five substituents independently selected from the group consisting of Ci-20-alkyl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , N R ^a R ^b , N R ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ,

5 to 14 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci-20-alkyl, C ₆ -io-aryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(O)- R ^a , NR ^a R ^b , N R ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ , wherein

R ^a and R ^b are independently selected from the group consisting of H and Ci-20-alkyl,

Ci-20-alkyl can be substituted with one to five substituents selected from the group consist- ing of phenyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ],

N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , and,

C6-io-aryl and 5 to 10 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci-10-alkyl, OR ^c , OC(0)-R ^c , C(O)- OR ^c , C(0)-R ^c , NR ^c R ^d , N R ^c [C(0)R ^d ], N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , wherein

R ^c and R ^d are independently selected from the group consisting of H and Ci-10-alkyl, wherein

Ci-10-alkyl can be substituted with one to five substituents selected from the group consisting of halogen, CN and NO2. More preferred are compounds of formula

wherein

R ¹ and R ² are independently from each other selected from the group consisting of C6-i4-aryl, and 5 to 14 membered heteroaryl, and

R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are independently from each other selected from the group consisting of H and Ci-30-alkyl, wherein

Ci-3o-alkyl can be substituted with one to nine substituents independently selected from the group consisting of C ₆ -io-aryl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ; and one or more CH ₂ -groups, but not adjacent CH ₂ -groups of Ci-30-alkyl and not the CH2-group directly attached to the core of the compound of formula (1 ), can be replaced by O or S, and

Ce-14-aryl can be substituted with one to five substituents independently selected from the group consisting of Ci- ₂₀ -alkyl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ,

5 to 14 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci- ₂₀ -alkyl, C ₆ -io-aryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(O)- R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ , wherein

R ^a and R ^b are independently selected from the group consisting of H and Ci- ₂ o-alkyl, Ci- ₂ o-alkyl can be substituted with one to five substituents selected from the group consisting of phenyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ],

N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , and,

C6-io-aryl and 5 to 10 membered heteroaryl can be substituted with one to five substitu- ents independently selected from the group consisting of Ci-10-alkyl, OR ^c , OC(0)-R ^c , C(O)-

OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ], N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , wherein

R ^c and R ^d are independently selected from the group consisting of H and Ci-10-alkyl, wherein

Ci-io-alkyl can be substituted with one to five substituents selected from the group consisting of halogen, CN and NO2.

Even more preferred are compounds of formula

R ¹ and R ² are independently from each other selected from the group consisting of C6-i4-aryl, and 5 to 14 membered heteroaryl, and

R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are independently from each other selected from the group consisting of H and Ci-30-alkyl, wherein

Ci-3o-alkyl can be substituted with one to nine substituents independently selected from halogen, preferably F, and

Ce-14-aryl can be substituted with one to five substituents independently selected from C1-20- alkyl.

Most preferred are compounds of formula

wherein R ¹ and R ² are independently from each other selected from the group consisting of phenyl, which can be substituted with one or two substituents independently selected from Ci-20-alkyl, and

R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are independently from each other selected from the group consisting of H and CF3.

In particular preferred are the following compounds

(1a)

(1c)

10

15

(1 d)

Also part of the invention is a process for the preparation of the compounds of formula 1

wherein

R ¹ and R ² are independently from each other selected from the group consisting of H , C1-30- alkyl, C2-3o-alkenyl, C2-3o-alkynyl, Cs-s-cycloalkyl, Cs-s-cycloalkenyl, 5 to 14 membered heterocycloalkyi, 5 to 14 membered heterocycloalkenyl, C6-i4-aryl and 5 to 14 membered heteroaryl, and

R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are independently from each other selected from the group consisting of H, Ci-30-alkyl, C2-3o-alkenyl, C2-3o-alkynyl, Cs-s-cycloalkyl, Cs-s-cycloalkenyl, 5 to 14 membered heterocycloalkyi, 5 to 14 membered heterocycloalkenyl, C6-i ₄ -aryl, 5 to 14 membered heteroaryl, halogen, CN, -SCN, N0 ₂ , OH, O-Ci-30-alkyl, 0-C ₂ - ₃ o-alkenyl, 0-C ₂ - ₃ o-alkynyl, 0-C5-8-cycloalkyl, O-Cs-s-cycloalkenyl, 0-5 to 14 membered heterocycloalkyi, 0-5 to 14 membered heterocycloalkenyl, 0-C6-i4-aryl, 0-5 to 14 membered heteroaryl, SH, S-Ci-30-alkyl, S-C2-3o-alkenyl, S-C2-3o-alkynyl, S-Cs-s-cycloalkyl, S-Cs-s-cycloalkenyl, S-5 to 14 membered heterocycloalkyi, S-5 to 14 membered heterocycloalkenyl, S-C6-i4-aryl, S-5 to 14 membered heteroaryl, C(0)H, CO-Ci-3o-alkyl, CO-C ₂ - ₃ o-alkenyl, CO-C ₂ - ₃ o-alkynyl, CO-C ₅ - ₈ -cycloalkyl, CO-C ₅ - ₈ - cycloalkenyl, CO-5 to 14 membered heterocycloalkyl, CO-5 to 14 membered heterocycloal- kenyl, CO-C ₆ -i ₄ -aryl, CO-5 to 14 membered heteroaryl, COOH, NH(Ci- ₃₀ -alkyl), N(Ci- ₃₀ -alkyl) ₂ , CONH ₂ , CONH(Ci- ₃₀ -alkyl), CON(Ci- ₃₀ -alkyl) ₂ , S0 ₂ OH, S0 ₂ NH ₂ , SO ₂ -Ci- ₃₀ -alkyl and S0 ₂ -C ₆ -i - aryl, wherein

Ci-3o-alkyl, C ₂ -3o-alkenyl and C ₂ -3o-alkynyl, can be substituted with one to nine substituents independently selected from the group consisting of Cs-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, Ce-10-aryl, 5 to 10 mem- bered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ; and one or more CH ₂ -groups, but not adjacent CH ₂ -groups of Ci-30-alkyl, C ₂ -3o-alkenyl and C ₂ -3o-alkynyl, and not the CH ₂ -group directly attached to the core of the compound of formula (1 ), can be replaced by O or S, and C5-8-cycloalkyl, Cs-8-cycloalkenyl, 5 to 14 membered heterocycloalkyl and 5 to 14 membered heterocycloalkenyl can be substituted with one to five substituents independently selected from the group consisting of Ci- ₂ o-alkyl, C ₂ - ₂ o-alkenyl, C ₂ - ₂ o-alkynyl, Ce-10-aryl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ,

C6-i ₄ -aryl can be substituted with one to five substituents independently selected from the group consisting of Ci- ₂ o-alkyl, C ₂ - ₂ o-alkenyl, C ₂ - ₂ o-alkynyl, Cs-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, and 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ,

5 to 14 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci- ₂ o-alkyl, C ₂ - ₂ o-alkenyl, C ₂ - ₂ o-alkynyl, Cs-6-cycloalkyl, C5-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, Ce-io-aryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ , wherein

R ^a and R ^b are independently selected from the group consisting of H, Ci- ₂ o-alkyl,

C ₂ - ₂ o-alkenyl and C ₂ - ₂ o-alkynyl,

Ci- ₂ o-alkyl, C ₂ - ₂ o-alkenyl and C ₂ - ₂ o-alkynyl can be substituted with one to five substituents selected from the group consisting of phenyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ], N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , and,

C5-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, Ce-10-aryl and 5 to 10 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci-10-alkyl, C2- 10-alkenyl, C ₂ -io-alkynyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ], N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , wherein

R ^c and R ^d are independently selected from the group consisting of H, Ci-10-alkyl, C2-io-alkenyl and C2-io-alkynyl,

wherein

Ci-10-alkyl, C2-io-alkenyl and C2-io-alkynyl can be substituted with one to five substituents selected from the group consisting of halogen, CN and NO2, which process comprises the steps of i) reducing a compound of formula 2

wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are as defined for the compound of formula 1 , to the compound of formula 2'

wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are as defined for the compound of formula 1 , and ii) treating the compound of formula 2' with a suitable catalyst to obtain a compound of formula 1 .

Preferably, the first step includes treating the compound of formula 2 with a suitable catalyst such as SnC in the presence of a suitable solvent such as ethyl acetate. Preferably, the first step is carried out at elevated temperatures, such as at temperatures from 50 to 150 °C, preferably 60 to 100 °C.

Preferably, the suitable catalyst of the second step is titanium tetrachloride. Preferably, the second step includes treating compound 2' with titanium tetrachloride as catalyst, and a suitable base such as DABCO in a suitable solvent such as mesitylene. Preferably, the second step is carried out at elevated temperatures, such as at temperatures from 80 to 180 °C, preferably 100 to 150 °C.

The compound of formula 2

wherein

R ¹ and R ² are independently from each other selected from the group consisting of H, C1-30- alkyl, C2-3o-alkenyl, C2-3o-alkynyl, Cs-s-cycloalkyl, Cs-s-cycloalkenyl, 5 to 14 membered heterocy- cloalkyl, 5 to 14 membered heterocycloalkenyl, C6-i ₄ -aryl and 5 to 14 membered heteroaryl, and R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are independently from each other selected from the group consisting of H, Ci-30-alkyl, C2-3o-alkenyl, C2-3o-alkynyl, Cs-s-cycloalkyl, Cs-s-cycloalkenyl, 5 to 14 membered heterocycloalkyl, 5 to 14 membered heterocycloalkenyl, C6-i ₄ -aryl, 5 to 14 membered heteroaryl, halogen, CN, -SCN, N0 ₂ , OH, O-Ci-30-alkyl, 0-C ₂ - ₃ o-alkenyl, 0-C ₂ - ₃ o-alkynyl,

0-C5-8-cycloalkyl, O-Cs-s-cycloalkenyl, 0-5 to 14 membered heterocycloalkyl, 0-5 to 14 mem- bered heterocycloalkenyl, 0-C6-i4-aryl, 0-5 to 14 membered heteroaryl, SH, S-Ci-30-alkyl,

S-C2-3o-alkenyl, S-C2-3o-alkynyl, S-Cs-s-cycloalkyl, S-Cs-s-cycloalkenyl, S-5 to 14 membered heterocycloalkyl, S-5 to 14 membered heterocycloalkenyl, S-C6-i4-aryl, S-5 to 14 membered heteroaryl, C(0)H, CO-Ci-3o-alkyl, CO-C ₂ - ₃ o-alkenyl, CO-C ₂ - ₃ o-alkynyl, CO-C ₅ - ₈ -cycloalkyl, CO-Cs-s- cycloalkenyl, CO-5 to 14 membered heterocycloalkyl, CO-5 to 14 membered heterocycloal- kenyl, CO-Ce- -aryl, CO-5 to 14 membered heteroaryl, COOH, NH(Ci- ₃₀ -alkyl), N(Ci- ₃₀ -alkyl) ₂ , CONH ₂ , CONH(Ci- ₃₀ -alkyl), CON(Ci- ₃₀ -alkyl) ₂ , S0 ₂ OH, S0 ₂ NH ₂ , SO ₂ -Ci- ₃₀ -alkyl and S0 ₂ -C ₆ -i ₄ - aryl, wherein

Ci-3o-alkyl, C ₂ -3o-alkenyl and C ₂ -3o-alkynyl, can be substituted with one to nine substituents independently selected from the group consisting of Cs-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, C6-io-aryl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ; and one or more CH ₂ -groups, but not adjacent CH ₂ -groups of Ci-30-alkyl, C ₂ -3o-alkenyl and C ₂ -3o-alkynyl, and not the CH ₂ -group directly attached to the core of the compound of formula (1 ), can be replaced by O or S, and

C5-8-cycloalkyl, Cs-8-cycloalkenyl, 5 to 14 membered heterocycloalkyl and 5 to 14 membered heterocycloalkenyl can be substituted with one to five substituents independently selected from the group consisting of Ci- ₂ o-alkyl, C ₂ - ₂ o-alkenyl, C ₂ - ₂ o-alkynyl, C6-io-aryl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ,

Ce-14-aryl can be substituted with one to five substituents independently selected from the group consisting of Ci- ₂ o-alkyl, C ₂ - ₂ o-alkenyl, C ₂ - ₂ o-alkynyl, Cs-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, and 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ,

5 to 14 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci- ₂ o-alkyl, C ₂ - ₂ o-alkenyl, C ₂ - ₂ o-alkynyl, Cs-6-cycloalkyl, C5-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, Ce-io-aryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ , wherein

R ^a and R ^b are independently selected from the group consisting of H, Ci- ₂ o-alkyl,

C ₂ - ₂ o-alkenyl and C ₂ - ₂ o-alkynyl,

Ci- ₂ o-alkyl, C ₂ - ₂ o-alkenyl and C ₂ - ₂ o-alkynyl can be substituted with one to five substituents selected from the group consisting of phenyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ], N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , and,

C5-6-cycloalkyl, Cs-6-cycloal kenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, Ce-10-aryl and 5 to 10 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci-10-alkyl, C ₂ - io-alkenyl, C _2- io-alkynyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ],

N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , wherein

R ^c and R ^d are independently selected from the group consisting of H, Ci-10-alkyl, C2-io-alkenyl and C2-io-alkynyl,

wherein

Ci-io-alkyl, C2-io-alkenyl and C2-io-alkynyl can be substituted with one to five substit- uents selected from the group consisting of halogen, CN and NO2, can be prepared by treating a compound of formula 3

wherein R ¹ and R ² are as defined for the compound of formula 2, with compounds of formulae 4 and 4'

wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are as defined for the compound of formula 2. Preferably, the reaction is carried out in the presence of a base such as K2CO3, and in the presence of a suitable solvent, such as DMF. Preferably, the reaction is carried out at elevated temperatures, such as at temperatures from 50 to 150 °C, preferably 60 to 100 °C.

The compound of formula 3 can be prepared as described by Potrawa, T.; Langhals, H. Chem. Ber. 1987, 120, 1075-1078, and Woo, C.H.; Beaujuge, P.M.; Holcombe, T.W.; Lee, O.P.;

Frechet, J.M.J. J. Am. Chem. Soc. 2010, 132, 15547-15549.

Also part of the invention are the intermediate compounds of formula 2

(2) wherein

R ¹ and R ² are independently from each other selected from the group consisting of H, C1-30- alkyl, C2-3o-alkenyl, C2-3o-alkynyl, Cs-s-cycloalkyl, Cs-s-cycloalkenyl, 5 to 14 membered heterocycloalkyi, 5 to 14 membered heterocycloal kenyl, C6-i ₄ -aryl and 5 to 14 membered heteroaryl, and R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are independently from each other selected from the group consisting of H, Ci-30-alkyl, C2-3o-alkenyl, C2-3o-alkynyl, Cs-s-cycloalkyl, Cs-s-cycloalkenyl, 5 to 14 membered heterocycloalkyi, 5 to 14 membered heterocycloalkenyl, C6-i ₄ -aryl, 5 to 14 membered heteroaryl, halogen, CN, -SCN, N0 ₂ , OH, O-Ci-30-alkyl, 0-C ₂ - ₃ o-alkenyl, 0-C ₂ - ₃ o-alkynyl, 0-C5-8-cycloalkyl, O-Cs-s-cycloalkenyl, 0-5 to 14 membered heterocycloalkyi, 0-5 to 14 mem- bered heterocycloalkenyl, 0-C6-i4-aryl, 0-5 to 14 membered heteroaryl, SH, S-Ci-30-alkyl,

S-C2-3o-al kenyl, S-C2-3o-alkynyl, S-Cs-s-cycloalkyl, S-Cs-s-cycloalkenyl, S-5 to 14 membered heterocycloalkyi, S-5 to 14 membered heterocycloalkenyl, S-C6-i4-aryl, S-5 to 14 membered heteroaryl, C(0)H, CO-Ci-3o-alkyl, CO-C ₂ - ₃ o-alkenyl, CO-C ₂ - ₃ o-alkynyl, CO-C ₅ - ₈ -cycloalkyl, CO-Cs-s- cycloalkenyl, CO-5 to 14 membered heterocycloalkyi, CO-5 to 14 membered heterocycloal- kenyl, CO-C ₆ -i ₄ -aryl, CO-5 to 14 membered heteroaryl, COOH, NH(Ci- ₃₀ -alkyl), N(Ci- ₃ o-alkyl) ₂ , CON H2, CONH(Ci- ₃₀ -alkyl), CON(Ci- ₃₀ -alkyl) ₂ , S0 ₂ OH, SO2N H2, SO ₂ -Ci- ₃₀ -alkyl and S0 ₂ -C ₆ -i ₄ - aryl, wherein Ci-3o-alkyl, C2-3o-alkenyl and C2-3o-alkynyl, can be substituted with one to nine substituents independently selected from the group consisting of Cs-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, C6-io-aryl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ; and one or more CH ₂ -groups, but not adjacent Ch -groups of Ci-30-alkyl, C2-3o-alkenyl and C2-3o-alkynyl, and not the CH2-group directly attached to the core of the compound of formula (1 ), can be replaced by O or S, and

C5-8-cycloalkyl, Cs-8-cycloalkenyl, 5 to 14 membered heterocycloalkyl and 5 to 14 membered heterocycloalkenyl can be substituted with one to five substituents independently selected from the group consisting of Ci-20-alkyl, C2-2o-alkenyl, C2-2o-alkynyl, Ce-10-aryl, 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ , Ce-14-aryl can be substituted with one to five substituents independently selected from the group consisting of Ci-20-alkyl, C2-2o-alkenyl, C2-2o-alkynyl, Cs-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, and 5 to 10 membered heteroaryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ],

N[C(0)R ^a ][C(0)R ^b ], halogen, CN and N0 ₂ ,

5 to 14 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci-20-alkyl, C2-2o-alkenyl, C2-2o-alkynyl, Cs-6-cycloalkyl, C5-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, Ce-io-aryl, OR ^a , OC(0)-R ^a , C(0)-OR ^a , C(0)-R ^a , NR ^a R ^b , NR ^a [C(0)R ^b ], N[C(0)R ^a ][C(0)R ^b ], hal- ogen, CN and N0 ₂ , wherein

R ^a and R ^b are independently selected from the group consisting of H, Ci-20-alkyl,

C2-2o-alkenyl and C2-2o-alkynyl,

Ci-2o-alkyl, C2-2o-alkenyl and C2-2o-alkynyl can be substituted with one to five substituents selected from the group consisting of phenyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ], N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , and, C5-6-cycloalkyl, Cs-6-cycloalkenyl, 5 to 10 membered heterocycloalkyl, 5 to 10 membered heterocycloalkenyl, Ce-10-aryl and 5 to 10 membered heteroaryl can be substituted with one to five substituents independently selected from the group consisting of Ci-10-alkyl, C2- 10-alkenyl, C ₂ -io-alkynyl, OR ^c , OC(0)-R ^c , C(0)-OR ^c , C(0)-R ^c , NR ^c R ^d , NR ^c [C(0)R ^d ], N[C(0)R ^c ][C(0)R ^d ], halogen, CN and N0 ₂ , wherein R ^c and R ^d are independently selected from the group consisting of H, Ci-10-alkyl, C2-io-alkenyl and C2-io-alkynyl,

wherein

Ci-io-alkyl, C2-io-alkenyl and C2-io-alkynyl can be substituted with one to five substit- uents selected from the group consisting of halogen, CN and NO2.

Also part of the present invention is an electronic device comprising the compound of formula 1 . Preferably, the electronic device is an organic field effect transistor (OFET).

Usually, an organic field effect transistor comprises a dielectric layer, a semiconducting layer and a substrate. In addition, an organic field effect transistor usually comprises a gate electrode and source/drain electrodes. Preferably, the semiconducting layer comprises the compound of formula 1. The semiconducting layer can have a thickness of 5 to 500 nm, preferably of 10 to 100 nm, more preferably of 20 to 50 nm.

The dielectric layer comprises a dielectric material. The dielectric material can be silicon dioxide or aluminium oxide, or, an organic polymer such as polystyrene (PS), poly(methylmethacrylate) (PMMA), poly(4-vinylphenol) (PVP), polyvinyl alcohol) (PVA), benzocyclobutene (BCB), or poly- imide (PI). The dielectric layer can have a thickness of 10 to 2000 nm, preferably of 50 to 1000 nm, more preferably of 100 to 800 nm. The dielectric layer can in addition to the dielectric material comprise a self-assembled monolayer of organic silane derivates or organic phosphoric acid derivatives. An example of an organic silane derivative is octyltrichlorosilane. An examples of an organic phosphoric acid derivative is octyldecylphosphoric acid. The self-assembled monolayer comprised in the dielectric layer is usually in contact with the semiconducting layer.

The source/drain electrodes can be made from any suitable source/drain material, for example gold (Au) or tantalum (Ta). The source/drain electrodes can have a thickness of 1 to 100 nm, preferably from 20 to 70 nm. The gate electrode can be made from any suitable gate material such as highly doped silicon, aluminium (Al), tungsten (W), indium tin oxide, gold (Au) and/or tantalum (Ta). The gate electrode can have a thickness of 1 to 200 nm, preferably from 5 to 100 nm.

The substrate can be any suitable substrate such as glass, or a plastic substrate such as poly- ethersulfone, polycarbonate, polysulfone, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). Depending on the design of the organic field effect transistor, the gate electrode, for example highly doped silicon can also function as substrate. The organic field effect transistor can be prepared by methods known in the art.

For example, a bottom-gate organic field effect transistor can be prepared as follows: The die- lectric material, for example AI2O3 or silicon dioxide, can be applied as a layer on a gate electrode such as highly doped silicon wafer, which also functions as substrate, by a suitable deposition method such as atom layer deposition or thermal evaporation. A self-assembled monolayer of an organic phosphoric acid derivative or an organic silane derivative can be applied to the layer of the dielectric material. For example, the organic phosphoric acid derivative or the organic silane derivative can be applied from solution using solution-deposition techniques. The semiconducting layer can be formed by either solution deposition or thermal evaporation in vacuo of a compound of formula 1 on the self-assembled monolayer of the organic phosphoric acid derivative or the organic silane derivative. Source/drain electrodes can be formed by deposition of a suitable source/drain material, for example tantalum (Ta) and/or gold (Au), on the semicon- ducting layer through a shadow masks. The channel width (W) is typically 50 μΐτι and the channel length (L) is typically 1000 μΐτι.

Also part of the invention is the use of the compound of formula 1 as semiconducting material.

The compounds of formula 1 show a high chemical stability under ambient temperature, air and light conditions. A high chemical stability means that no or almost no chemical modifications, such as oxidation, degradation or dimerization, of the compounds of formula 1 is observed over time. In addition, the compounds of formula 1 are stable upon heating to temperatures up to 70 °C for up to several hours, for example the time required to measure a ¹³ C NMR, without noticable decomposition.

In addition, the compounds of formula 1 are soluble in organic solvents and thus are compatible with liquid processing techniques. For example, the compound of formula 1 b is soluble in common organic solvents such as chloroform, toluene and tetrahydrofurane at ambient temperature. The compounds of formulae 1 c and 1 d dissolve well in warm organic solvents.

Furthermore, the compounds of formula 1 are suitable as semiconducting material in electronic devices, in particular in organic field effect transistors (OFETs). Examples

Example 1

Preparation of compound 1 a

(1a)

Preparation of compound 3a

Compound 3a was prepared as described by Potrawa, T.; Langhals, H . Chem. Ber. 1987, 120, 1075-1078.

Preparation of compound 2a

A mixture of DPP 3a (400 mg, 1 .39 mmol), 2-fluoro-5-trifluoromethyl-nitrobenzene (0.78 mL, 5.56 mmol) and K ₂ C0 ₃ (770 mg, 5.56 mmol) in DMF (200 mL) was stitrred at 70 °C for 22 h, and the suspension became clear when the reaction is finished. Afterwards K2CO3 was removed by filtration and the solvent was removed by reduced pressure to get the crude product. Methanol (10 mL) was added to the crude product and the precipitate was filtered, washed with methanol (10 mL) until it became colorless, and dried under vacuum to get compound 2a as a yellow solid (490 mg, 53%).

¹ H NMR ([D ₆ ]DMSO, 400 MHz, 300 K): δ = 8.60 (d, ⁴ J = 1 .8 Hz, 0.9 H), 8.53 (d, ⁴ J = 1 .8 Hz, 1.1 H) , 8.25 (dd, ⁴ J = 1.8 Hz, ³ J = 8.7 Hz, 1.1 H), 8.18 (dd, ⁴ J = 1 .6 Hz, ³ J = 8.4 Hz, 0.9 H), 7.86 (d, ³ J = 8.1 Hz , 1 .1 H), 7.62-7.44 (m, 10.9 H); the ratio of the isomers is = 0.9/1.1. ¹³ C NMR

([D ₆ ]DMSO, 150 MHz, 343 K): δ = 161.9, 159.4, 159.3, 146.5, 145.9, 145.7, 132.7, 132.0, 131 .9, 131 .8, 131.5, 131.4, 130.6, 130.54, 130.52, 129.8, 129.5, 128.9, 128.75, 128.67, 128.6, 125.7, 125.6, 125.0, 123.2, 122.8, 122.7, 122.54, 122.51 , 121 .4, 109.84, 109.79. MS (MALDI TOF, neg. mode, CHCI3): mlz. calculated for C32H16F6N4O6: 666.105 [M] , found: 666.039. HRMS (ESI, pos. mode, acetonitrile/chloroform 1 :1 ): m/z. calculated for C32H17F6N4O6: 667.1052 [M+H] ⁺ , found: 667.1050. CV (CH ₂ CI ₂ , 0.1 M TBAHFP, vs. Fc/Fc ⁺ ): £ ^red (X/X )= -1 .43 V, £i ₂ ^ox (X X ⁺ ) = 1 .04 V. UV-Vis (CHCI3): (ε) = 464 (23800 M ¹ cm ¹ ).

Preparation of compound 1a

A mixture of compound 2a (120 mg, 0.18 mmol), and SnCI ₂ ^« 2H ₂ 0 (410 mg, 1.8 mmol) in ethyl acetate (25 mL) was heated at 78 °C for 3 h under argon. After the solution was cooled down to room temperature, the pH is made slightly basic (pH 7-8) by addition of 10 % aqueous sodium bicarbonate before extracting with ethyl acetate. The organic phase was collected and dried over magnesium sulfate, and the solvent was removed under reduced pressure to get the crude product, which was washed with methanol (5 mL) and dried under vacuum to get the desired intermediate product diamine-DPP, which was used for the next step without further purification. The crude diamine-DPP from previous step (1 10 mg) and DABCO (90 mg, 0.80 mmol) were dissolved in mesitylene (70 mL) while heating to 120 °C for 10 min. Titanium tetrachloride (0.14 mL, 1 .30 mmol) in mesitylene (2 mL) was added dropwise to the reaction mixture and the solution was kept at 120 °C for additional 30 min. The hot reaction was dropped quickly in to 50 mL water, extracted with a small amount of ethyl acetate, and the organic phase was passed through a neutral aluminum oxide column using chloroform as eluent. The solvent was removed under vacuum and the residue was washed with 2 mL methanol to obtain the pure compound 1 a as a red solid (15 mg). The total yield of the two steps from compound 2a to 1 a is 15 %. ¹ H NMR ([D ₂ ]tetrachloroethane, 600 Hz, 353 K): δ = 8.15 (d, ³ J = 7.4 Hz, 4 H), 7.96 (s, 2 H), 7.70- 7.65 (m, 6 H), 7.45 (d, ³ J = 8.5 Hz, 2 H), 7.39 (d, ³ J = 8.5 Hz, 2 H). ¹³ C NMR

([D ₂ ]tetrachloroethane, 150 Hz, 343 K): δ = 139.3, 133.5, 132.4, 129.6, 129.5, 127.2, 126.0, 125.6, 124.0, 121.4, 121 .3, 120.6, 1 19.1 , 1 19.1 , 120.0, 1 17.7, 1 16.9, 1 16.7, 1 16.5, 1 12.2. MS (MALDI TOF, neg. mode, CHCI ₃ ): mlz. calculated for C ₃₂ Hi6F6N ₄ : 570.128 [M]-, found: 570.1 10. HRMS (ESI, pos. mode, acetonitrile/chloroform 1 :1 ): mlz. calculated for C ₃₂ Hi ₇ F6N ₄ : 571.1357 [M+H] ⁺ , found: 571.1353. CV (CH ₂ CI ₂ , 0.1 M TBAHFP, vs. Fc/Fc ⁺ ): £i ₂ ^red (X/X ) = -1.31 V, E° ^x (X X ⁺ ) = 0.99 V. UV-Vis (CHCI3): _ma Jnm (ε) = 484 (15700 M ¹ cm ¹ ). Example 2

Preparation of compound 1 b

tert-Bu

Preparation of compound 3b

Compound 3b was prepared as described by Potrawa, T.; Langhals, H. Chem. Ber. 1987, 120, 1075-1078. Preparation of compound 2b

A mixture of DPP 3b (200 mg, 0.5 mmol), 2-fluoro-5-trifluoromethyl-nitrobenzene (0.28 mL, 2 mmol) and K ₂ C0 ₃ (276 mg, 2 mmol) in DM F (100 mL) was stirred at 70 °C for 24 h. After the reaction solution was cooled down to room temperature, K ₂ CC>3was removed by filtration and the solvent was removed under reduced pressure to get the crude product. Methanol was added to the latter and the precipitate was filtered, washed with methanol until it became colorless and dried under vacuum to obtain compound 2b as a red solid (195 mg, 50 %).

¹ H NMR: (CDCI ₃ , 400 Hz, 300 K): δ = 8.39 (d, ⁴ J = 1 .7 Hz, 0.8 H), 8.34 (d, ⁴ J = 1 .8 Hz, 1 .2 H) , 7.91 (dd, ⁴ J = 1 .6 Hz, ³ J =8.4 Hz, 1.2 H), 7.79 (dd, ⁴ J = 1 .6 Hz, ³ J = 8.4 Hz, 0.8 H), 7.60-7.58 (m, 1.6 H), 7.54-7.48 (m, 3.6 H), 7.40-7.36 (m, 4 H), 7.20 (d, ³ J =8.3 Hz, 0.8 H), 1.30 (s, 7.2 H), 1.29 (s, 10.8 H). The ratio of the isomers is = 0.8/1.2. ¹³ C NMR (CDCI ₃ , 100 Hz, 300 K): δ = 160.3, 160.1 , 156.4, 156.3, 146.8, 146.7, 146.3, 145.9, 132.7, 132.6, 131.9, 131.5, 131.2, 131.1 , 130.9, 130.3, 130.26, 130.23, 129.8, 129.5, 129.2, 126.14, 126.09 123.8, 123.4, 123.2, 122.99, 122.95 121.1 , 1 10.8, 1 10.5, 31 .0, 30.9. H RMS (ESI, pos. mode, acetonitrile/chloroform 1 :1 ): m/z: calculated for C40H33F6N4O6: 779.2304 [M+H] ⁺ , found: 779.2301. CV (CH ₂ CI ₂ , 0.1 M TBAHFP, vs. Fc/Fc ⁺ ): £ ^red (X X )= -1.53 V, £i ₂ ^ox (X X ⁺ ) = 0.94 V. UV-Vis (CHC ): _ma Jnm (ε) = 483 (29600 M ¹ cm ¹ ). Preparation of compound 1b

A mixture of compound 2b (1 10 mg, 0.14 mmol), and SnCI ₂ ^« 2H ₂ 0 (320 mg, 2.6 mmol) in ethyl acetate (25 mL) was heated at 78 °C for 3 h under argon. After the solution was cooled down to room temperature, the pH is made slightly basic (pH 7-8) by the addition of 10 % aqueous sodium bicarbonate before extracting with ethyl acetate. The organic phase was separated and dried over magnesium sulfate, and the solvent was evaporated under reduced pressure to get the crude product, which was washed with methanol and dried under vacuum to get the desired product diamine-DPP, which was used in the next step without further purification. The crude diamine-DPP from the previous step (100 mg) and DABCO (1 10 mg, 1 .0 mmol) were dissolved in mesitylene (100 mL) while heating to 120 °C for 10 min. Titanium tetrachloride (0.18 mL, 1.65 mmol) in mesitylene (2 mL) was added dropwise to the reaction mixture, the solution was kept at 120 °C for about 50 min. After the reaction was finished, the hot solution was dropped immediately into 50 mL water, and extracted with a small amount of ethyl acetate. The organic phase was passed through a neutral aluminum oxide column using chloroform as eluent and the solvent was removed under reduced pressure. The residue was washed with methanol (2 mL) to get the compound 1 b as a red solid (13 mg). The total yield of the two steps from 2b to 1 b is 14%.

¹ H NMR (CDCI3, 400 Hz, 300 K): δ = 8.12 (d, ³ J = 8.3 Hz, 4 H), 8.00 (s, 2 H), 7.75 (d, ³ J = 8.5 Hz, 2 H), 7.56 (d, ³ J =8.5 Hz, 2 H). 7.43 (d, ³ J =8.5 Hz, 2 H), 1 .26 (s, 18 H). ¹³ C NMR (CDCI3, 100 Hz, 300 K): δ = 155.1 , 152.4, 148.3, 138.1 , 135.4, 132.1 , 128.0, 125.5, 125.0, 124.7, 124.6, 123.0, 122.0, 1 19.9, 1 17.6, 1 17.6, 1 15.7, 1 1 1 .1 , 30.2, 28.7. MS (MALDI TOF, neg. mode, CHCI3): m/z. calculated for C4oH3 ₂ F ₆ N ₄ : 682.253 [M]-, found: 682.232. HRMS (ESI, pos. mode, acetonitrile/chloroform 1 :1 ): mlz. calculated for C40H33F6N4: 683.2610 [M+H] ⁺ , found: 683.2610. CV (CH2CI2, 0.1 M TBAHFP, vs. Fc/Fc ⁺ ): £i ₂ ^red (X/X ) = -1 .39 V, E° ^x (X/X ⁺ ) = 0.96 V. UV-Vis (CHCI3): (ε) = 494 (24900 M ¹ cm ¹ ).

Example 3

Preparation of compound 1 c

00

Preparation of compound 3c

Compound 3c was prepared as described by Woo, C.H .; Beaujuge, P.M.; Holcombe, T.W.; Lee, O.P.; Frechet, J.M.J. J. Am. Chem. Soc. 2010, 132, 15547-15549. Preparation of compound 2c

A mixture of DPP 3c (400 mg, 1 .33 mmol), 2-fluoro-5-trifluoromethyl-nitrobenzene (0.75 mL, 5.32 mmol) and K ₂ C0 ₃ (736 mg, 5.32 mmol) in DMF (50 mL) was stirred at 70 °C for 24 h. After the reaction was cooled down to room temperature, K2CO3 was removed by filtration, extracted twice with 5 mL chloroform, and the collected solvent was removed under reduced pressure. Methanol was added to the crude product and the precipitate was filtered, and washed with methanol until it became colorless, and dried under vacuum to get compound 2c as a red solid (489 mg, 54 %).

¹ H NMR ([D ₆ ]DMSO, 600 Hz, 350 K): δ = 8.69 (d, ⁴ J = 2.0 Hz, 0.8 H), 8.66 (d, ⁴ J = 2.0 Hz, 1 .2 H), 8.38-8.36 (m, 4 H), 8.25 (d, ³ J = 8.2 Hz, 1 .2 H), 8.10 (d, ³ J = 8.2 Hz, 0.8 H), 7.95-7.93 (m, 2 H), 7.29-7.27 (m, 2 H); the ratio of the isomers is = 0.8/1 .2. ¹³ C NMR ([D ₆ ]DMSO, 150 Hz, 343 K): δ = 161. 9, 159.2, 159.1 , 147.3, 147.2, 138.7, 38.6, 134.8, 134.7, 134.6, 134.30, 134.25, 134.1 , 131.5, 131.3, 131 .2, 131 .12, 131 .08, 128.4, 128.3, 128.2, 123.2, 123.0, 122.9, 122.8,

122.7, 121 .4, 107.2. MS (MALDI TOF, neg. mode, CHCI ₃ ): m/z: calculated for C28H12F6N4O6S2: 678.010 [M] , found: 678.991 . HRMS (ESI, pos. mode, acetonitrile/chloroform 1 :1 ): m/z.

calculated for C28H13F6N4O6S2: 679.0181 [M+H] ⁺ , found: 679.0174. CV (CH ₂ CI ₂ , 0.1 M TBAHFP, vs. Fc/Fc ⁺ ): £ ^red (X/X ) = D-1.37 V, E _V2 ^0X (X/X ⁺ ) = 0.76 V, E _1/2 ^0x (X ⁺ /X ²⁺ ) = 1 .09 V. UV-Vis (CHCI3): (ε) = 502 (29100), 537 (33000 M ¹ cm ¹ ).

Preparation of compound 1c

A mixture of compound 2c (130 mg, 0.20 mmol), and SnCI ₂ '2H ₂ 0 (344 mg, 2.6 mmol) in ethyl acetate (30 mL) was heated at 70 °C for 3 h under argon. After the solution was cooled down to room temperature, the pH was made slightly basic (pH 7-8) by the addition of 10 % aqueous sodium bicarbonate before extracting with ethyl acetate. The organic phase was separated and dried over magnesium sulfate. The solvent was removed under reduced pressure and the residue was dried under vacuum to get the desired product diamine-DPP, which was used for the next step without further purification. The crude product from the previous step (120 mg) and DABCO (140 mg, 1 .25 mmol) were dissolved in mesitylene (150 mL) while heating to 125 °C for 10 min. Titanium tetrachloride (0.18 mL, 1 .63 mmol) in mesitylene (2 mL) was added dropwise to the reaction mixture, the solution was kept at 125 °C for about 60 min. The hot reaction solution was dropped quickly into 50 mL water, extracted with a small amount of ethyl acetate, and the organic phase was passed through a neutral aluminum oxide column using chloroform as eluent. The solvent was removed under reduced pressure and the residue was washed with methanol to get pure 1 c as a dark brown solid (22 mg). The total yield of the two steps from 2c to 1 c is 20 %.

1H NMR ([D ₂ ]tetrachloroethane, 600 Hz, 350 K): δ = 8.50 (dd, ³ J = 3.7 Hz, ⁴ J = 0.8 Hz, 2 H), 8.01 -8.0 (m, 4 H), 7.78 (dd, ³ J = 5.0 Hz, ⁴ J = 0.9 Hz, 2 H), 7.46 (dd, ³ J = 8.5 Hz, ⁴ J = 1 .0 Hz, 2 H), 7.42-7.40 (m, 2 H). ¹³ C N MR ([D ₂ ]tetrachloroethane, 150 Hz, 343 K): δ = 153.3, 149.7,

134.8, 133.2, 132.3, 131.9, 129.6, 128.9, 126.4, 126.1 , 125.6, 123.9, 123.8, 121.30, 121.28, 120.6, 1 19.12, 1 19.09, 1 16.7, 1 16.5, 1 16.2, 1 12.5, 99.9, 80.1 , 80.0, 79.8. MS (MALDI TOF, neg. mode, CHC ): mlz. calculated for C28H12F6N4S2: 582.041 [M] ^D , found: 582.002. HRMS (ESI, pos. mode, acetonitrile/chloroform 1:1): mlz. calculated for C28H13F6N4S2: 583.0486. [M+H] ⁺ , found: 583.0483. CV (CH2CI2, 0.1 M TBAHFP, vs. Fc/Fc ⁺ ): £i ₂ ^red (XX )= -1.27 V, E ^0X (XJX ⁺ ) = 0.84 V, E° (X ⁺ /X ²⁺ ) = 1.02 V. UV-Vis (CHCI3): λ _m aχ/nm (ε) = 527 (25500 M ¹ cm ¹ ).

Example 4

Preparation of compound 1d

(1d) Preparation of compound 3d

Compound 3d was prepared as described by Woo, C.H.; Beaujuge, P.M.; Holcombe, T.W.; Lee, O.P.; Frechet, J.M.J. J. Am. Chem. Soc. 2010, 132, 15547-15549. Preparation of compound 2d

A mixture of DPP 3d (400 mg, 1.5 mmol), 2-fluoro-5-trifluoromethyl-nitrobenzene (0.64 mL, 6.0 mmol) and K ₂ C0 ₃ (828 mg, 3.0 mmol) in DMF (160 mL) was stirred at 70 °C for 5 h. K ₂ C0 ₃ was removed by filtration and the solvent was removed under reduced pressure. Methanol was added to the crude product and the solid was filtered, washed with methanol until it became color- less and dried under vacuum, affording 2d as a red solid (550 mg, 57 %).

¹ H NMR ([D ₆ ]DMSO, 600 Hz, 300 K): δ = 8.66 (d, ⁴ J = 2.0 Hz, 0.8 H), 8.63 (d, ⁴ J = 2.0 Hz , 1.2 H) , 8.39-8.36 (m, 2 H), 8.22 (d, ³ J = 8.2 Hz, 1 .2 H), 8.08 (d, ³ J = 8.2 Hz, 0.8 H), 7.89 (dd, ³ J = 1.6 Hz, ⁴ J = 0.5 Hz, 0.8 H), 7.87 (dd, ³ J = 1.6 Hz, ⁴ J = 0.5 Hz, 1 .2 H), 7.80-7.79 (m, 2 H), 6.84- 6.82 (m, 2 H); the ratio of the isomers = 0.8/1.2. ¹³ C NM R ([D ₆ ]DMSO, 150 Hz, 343 K): δ = 158.9, 148.6, 148.4, 146.7, 146.6, 142.5, 142.3, 133.7, 133.4, 132.7, 132.6, 132.3, 131.2, 131.1 , 130.6, 130.4, 123.7, 123.0, 122.8, 122.7, 121.9, 121.8, 120.6, 120.4, 1 14.1 , 1 14.0, 105.8, 54.9. HRMS (ESI, pos. mode, acetonitrile/chloroform 1 :1 ): mlz. calculated for

C28H13F6N4O8: 647.0638, [M+H] ⁺ , found: 647.0603. CV (CH ₂ CI ₂ , 0.1 M TBAHFP, vs. Fc/Fc ⁺ ): £ ^red (X/X ) = -1.39 V, £i 2 ^ox (X/X ⁺ ) = 0.75 V, (X ⁺ /X ²⁺ ) = 0.94 V. UV-Vis (CHC ): λ™ _χ /ηΓΠ (ε) = 492 (31400), 530 (46700 M ¹ cm ¹ ).

Preparation of compound 1d

This compound was synthesized from compound 2d by using the same procedure as applied for the synthesis of compound 1 c from 2c. Yield of 1 d: 17 %.

¹ H NMR ([D ₂ ]tetrachloroethane, 600 Hz, 350 K): δ = 8.39 (d, ³ J = 2.9 Hz, 2 H), 8.28 (d, ³ J = 8.4 Hz, 2 H), 7.98 (s, 2 H), 7.86 (2 H), 7.52 (d, ³ J = 8.4 Hz, 2 H). 6.89- 6.88 (m, 2 H). MS (MALDI TOF, neg. mode, CHCI3): mlz. calculated for C28H12F6N4O2: 550.086 [M]-, found: 550.013.

HRMS (ESI, pos. mode, acetonitrile/chloroform 1 :1 ): mlz. calculated for C28H13F6N4O2: 551.0943 [M+H] ⁺ , found: 551 .0936. CV (CH2CI2, 0.1 M TBAHFP, vs. Fc/Fc ⁺ ): £i ₂ ^red (X/X ) = -1.27 V, £ ^ox (X/X ⁺ ) = 0.72 V, £ ^ox (X ⁺ /X ²⁺ ) = 1.06 V. UV-Vis (CHCI ₃ ): _ma Jnm (ε) = 570 (28500 M ¹ cm ¹ ).

Example 5

Test of the chemical stability of compound 1 a

Compound 1 a was dissolved in chloroform (c = 9.0 x 10 ⁶ M), and stored under ambient air and light conditions at room temperature. UV-Vis absorption spectra of compound 1 a, dissolved in chloroform (c = 9.0 x 10 ⁶ M), were recorded after 0, 1 , 2, 3 and 4 days of storage at room temperature in a conventional quartz cell (light pass 10 mm) on a Perkin-Elmer Lambda 950 spectrometer. No chemical modification, such as degradation, was observed after 4 days. Example 6

Preparation of transistors comprising compound 1c as semiconducting material

Highly doped p-type silicon (100) wafers (0.01-0.02 Ω-cm) were used as substrates A. Highly doped p-type silicon (100) wafers (0.005-0.02 Ω-cm) with a 100 nm thick thermally grown Si0 ₂ layer (capacitance 34 nF/cm ² ) were used as substrates B.

Onto substrates A, a 30 nm thick layer of aluminum is deposited by thermal evaporation in a Leybold UNIVEX 300 vacuum evaporator from a tungsten wire, at a pressure of 2* 10 ^"6 mbar and with an evaporation rate of 1 nm/s. The surface of the aluminum layer is oxidized by a brief exposure to an oxygen plasma in an Oxford reactive ion etcher (RIE, oxygen flow rate: 30 seem, pressure: 10 mTorr, plasma power: 200 W, plasma duration 30 sec) and the substrate is then immersed into a 2-propanol solution of a phosphonic acid (1 mMol solution of Ci ₄ H ₂₉ PO(OH) ₂ [TDPA] or 1 mMol solution of C ₇ F ₁₅ C ₁₁ H ₂₂ PO(OH) ₂ [FODPA]) and left in the solution for 1 hour, which results in the formation of a self-assembled monolayer (SAM) of phosphonic acid mole- cules on the aluminum oxide surface. The substrate is taken out of the solution and rinsed with pure 2-propanol, dried in a stream of nitrogen and left for 10 min on a hotplate at a temperature of 100 °C. The total capacitance of the ΑΙΟχ/SAM gate dielectric on substrate A is 810 nF/cm ² in case of C ₁₄ H ₂₉ PO(OH) ₂ and 710 nF/cm ² in case of C ₇ F ₁₅ C ₁₁ H ₂ 2PO(OH) ₂ . On substrates B, an about 8 nm thick layer of Al ₂ 0 ₃ is deposited by atomic layer deposition in a Cambridge NanoTech Savannah (80 cycles at a substrate temperature of 250 °C). The surface of the aluminum oxide layer is activated by a brief exposure to an oxygen plasma in an Oxford reactive ion etcher (RIE, oxygen flow rate: 30 seem, pressure: 10 mTorr, plasma power: 200 W, plasma duration 30 sec) and the substrate is then immersed into a 2-propanol solution of a phosphonic acid (1 mMol solution of d ₄ H ₂₉ PO(OH) ₂ [TDPA] or 1 mMol solution of

C ₇ F ₁₅ Cii H ₂₂ PO(OH) ₂ [FODPA]) and left in the solution for 1 hour, which results in the formation of a self-assembled monolayer (SAM) of phosphonic acid molecules on the aluminum oxide surface. The substrate is taken out of the solution and rinsed with pure 2-propanol, dried in a stream of nitrogen and left for 10 min on a hotplate at a temperature of 100 °C. The total capaci- tance of the Si0 ₂ /AIO, SAM gate dielectric on substrate B is 32 nF/cm ² (independent on the choice of the phosphonic acid).

The contact angle of water on the TDPA-treated substrates is 108°, and on the FODPA-treated substrates 118°. A 30 nm thick film of the compound 1c is deposited by thermal sublimation in a Leybold UNI- VEX 300 vacuum evaporator from a molybdenum boat, at a pressure of 2* 10 ^"6 mbar and with an evaporation rate of 0.3 nm/s. For the source and drain contacts 30 nm of gold is evaporated through a shadow mask in a Leybold UNIVEX 300 vacuum evaporator from tungsten boat, at a pressure of 2* 10 ^"6 mbar and with an evaporation rate of 0.3 nm/s. The transistors have a channel length (L) ranging from 10 to 100 μηι and a channel width (W) ranging from 50 to 1000 μηι. To be able to contact the back side of the silicon wafer, the wafer (which also serves as the gate electrode of the transistors) is scratched on the back side and coated with silver ink.

Example 7

Measuring the electrical characteristics of the transistors of example 6

The electrical characteristics of the transistors of example 6 are measured on a Micromanipulator 6200 probe station using an Agilent 4156C semiconductor parameter analyzer. All measurements are performed in air at room temperature. The probe needles are brought into contact with the source and drain contacts of the transistors by putting them down carefully on top of the gold contacts. The gate electrode is contacted through the metal substrate holder onto which the wafer is placed during the measurements.

To obtain the transfer curve the drain-source voltage (V _DS ) is held to 3 V (in case of substrate A) or 40 V (in case of substrate B). The gate-source voltage V _G s is swept at medium speed from 0 to 3 V in steps of 0.03 V (substrate A) or from 0 to 40 V in steps of 0.4 V (substrate B) and back. The charge-carrier mobility is extracted in the saturation regime from the slope of (l _D ) ^{1 2} versus V _G s-

To obtain the output characteristics the drain-source voltage (V _DS ) is swept at medium speed from 0 to 3 V in steps of 0.03 V (substrate A) and from 0 to 40 V in steps of 0.4 V (substrate B), while the gate-source voltage V _G s is held at up to 8 different voltages (e.g. 0, 0.5, 1 , 1.5, 2, 2.5, 3 V in case of substrate A or 0, 10, 20, 30, 40 V in case of substrate B).

The results are depicted in Table 1.

Table 1.