BACKGROUND

Field of Invention

[0001] Some embodiments relate to improved gas, e.g. , oxygen sensors. Some embodiments relate to sensor materials incorporating carbazolyl benzenes.

Description of Related Art

[0002] The sensors of the present application may be used in the packaging industry and in particular in areas where integrity of the package is of particular interest. Such packages include food packaging in general, and specifically of food exports, particularly of high margin foods e.g. certain fish/shellfish, bulk food ingredients, wine, beer, long term food storage as required for emergency aid and military operations, in the catering industry, pharmaceutical industry and in the packaging of medical disposables, surgical instruments and pediatric products as well as in any sectors that required a clean room manufacturing or assembly environment. The sensors may also be used in situations the atmosphere is important to the product, such as protective atmospheres for art conservation or gas- sensitive, limited-life products such as DVDs. Other applications include monitoring of water quality, in-line production monitoring and in biofermentation reactors.

[0003] Currently used methods of checking the integrity of packages and the possible contamination of sterilized products involve destructive sampling in which a proportion of the packages are opened and tested for damage to the packaging for microbial contamination. However, this method only tests a small proportion of the packages and damaged packages could be present in the much larger proportion of packages not tested. Furthermore, the method destroys packages which may well have been intact and is therefore quite wasteful of both packages and their contents. [0004] Food products are often packed under a protective atmosphere of carbon dioxide, or modified atmospheric package (MAP). Often, but not always, the exclusion of oxygen is preferred in order to inhibit growth of aerobic spoilage organisms, whereas carbon dioxide is typically used to decrease bacterial growth rates. Because package integrity is an essential requirement for the quality of MAP food, leakage detection is a very important part of MAP technology. The standard method currently used to check the integrity of MAP involves the use of a MAP analyzer instrument. This involves piercing the package using a needle probe to withdraw a sample of the protective gas atmosphere. The gas is then analyzed using an electrochemical sensor to determine the oxygen concentration, and infrared spectrometry to determine the carbon dioxide concentration. As this is a destructive method, only a small percentage of the packages can be tested and so 100% quality control is not possible. Testing normally takes place at the packaging plant and is a validation of the packaging process. If a package is found to be leaking, what follows is a time consuming and costly process of back-checking and repacking. Once the packages leave the processing plant, there is no monitoring of the package integrity or freshness of the food (e.g. PBI-Dansensor MAP Check Combi or Systech Instruments Portamap2 or Gaspac).

[0005] Another instrument used to check for leak detection uses noninvasive methods. This involves placing the package into a pressure chamber and checking for leaks using carbon dioxide. It has the advantage of being nondestructive but is time-consuming and would not easily be incorporated into a production line. (e.g. PBI-Dansensor Pack Check). Thus there is a need for a simple and reversible optical sensor system for the detection of oxygen.

SUMMARY

[0006] The present embodiments include a gas sensor for use in packaging applications, as well as methods related to the gas sensor.

[0007] Some embodiments include a gas sensor, e.g., oxygen sensor, element comprising an emissive compound represented by Formula 1 :

Formula 1 wherein is H, -CF ₃ , optionally substituted phenyl, optionally substituted phenylethynyl, optionally substituted naphthyl, optionally substituted carbazolyl, optionally substituted pyridinyl, or optionally substituted pyrimidinyl; R ₂ is -CN or - CF _3;

R ₃ and R ₄ are independently optionally substituted carbazolyl, optionally substituted phenyl, or optionally substituted benzocarbazolyl; and R ₅ and R ₆ are independently optionally substituted carbazolyl, optionally substituted phenyl, or optionally substituted benzocarbazolyl.

[0008] Some embodiments include a method of detecting an oxygen- containing analyte in a sample comprising contacting the sample with a compound described herein; and detecting the presence or absence of blue emissions from the sample, wherein the presence of blue emissions indicates the absence of oxygen in the sample. In some embodiments the method can further comprise measuring the amount of blue emission in the sample and correlating the amount of blue emission from the sample with a concentration of the oxygen in the sample.

[0009] Some embodiments include a method for determining the presence of oxygen in a sealed cavity comprising forming a first layer comprising the described compounds, wherein the compound has a first and second form, the first and second chemical forms having different visual characteristics; forming the second layer adjacent to the first layer and isolating the first layer from contact with the ambient environment, wherein the presence of an unacceptable level of oxygen contacting the first layer causes a color change of the first layer.

[0010] Some embodiments include a colorimetric indicating film comprising a first layer first layer comprising the described compounds. In some embodiments, the film further comprises polymethylmethacrylate. In some embodiments, the film further comprises a second layer, wherein the first and second layers are adjacent to each other, and wherein the first and second layers define an internal cavity therein, and wherein the first layer is a first color in an oxygen deficient atmosphere and a second color in an oxygen present atmosphere.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 depicts singlet (S1 ) and triplet (T1 ) energy levels.

[0012] FIG. 2 is a schematic of an embodiment of a film described herein.

[0013] FIG. 3 is a schematic of an embodiment of a film described herein.

[0014] FIG. 4 is a schematic of an embodiment of a film described herein.

[0015] FIG. 5 is a schematic of an embodiment of a film described herein.

[0016] FIG. 6 is a comparative photograph of embodiments exposed and not exposed to a triplet quenching material, e.g., 0 ₂ .

[0017] FIG. 7 is a plot presenting the emissive intensities of an embodiment versus emissive wavelengths for EM-8.

[0018] FIG. 8 is a plot presenting the emissive intensities of a film embodiment versus varying triplet quenching material, 0 ₂ , concentrations.

[0019] FIG. 9 is a plot presenting the emissive intensities of a film embodiment versus varying triplet quenching material, 0 ₂ , concentrations.

DETAILED DESCRIPTION

[0020] By employing a newly designed molecular structure, an example shown below, we report gas sensing materials that can be used in gas sensor device applications.

[0021] As used herein, "optionally substituted" group refers to a group that may be substituted or unsubstituted, such as alkyl, naphthyl, carbazolyl, benzocarbazolyl, phenoxazolyl, phenothiazolyl, phenazolyl, etc. A substituted group is derived from the unsubstituted parent structure wherein one or more hydrogen atoms on the parent structure have been independently replaced by one or more substituent groups. A substituted group may have one or more substituent groups on the parent group structure. For example, some substituent groups may include optionally substituted alkyl, -O-alkyl (e.g. -OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ , etc.), -S- alkyl (e.g. -SCH ₃ , -SC ₂ H ₅ , -SC ₃ H ₇ , -SC ₄ H ₉ , etc.), -NR'R", wherein R' and R" are independently H or optionally substituted alkyl, -OH, -SH, -CN, -NO ₂ , -CF ₃ , phenyl, diphenyl amine, acenaphtyl, naphthyl, benzocarbazolyl, phenoxazolyl, phenothiazolyl, phenazolyl, phenylnaphthylamine, carbazolyl, F, CI, Br, or I. Wherever a substituent is described as "optionally substituted," that substituent can be substituted with the above substituents.

[0022] Optionally substituted alkyl includes its common meaning in the field and includes unsubstituted alkyl and substituted alkyl. The substituted alkyl refers to substituted alkyl where one or more H atoms are replaced by one or more substituent groups, such as -O-alkyl (e.g. -OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ , etc.), - S-alkyl (e.g. -SCH ₃ , -SC ₂ H ₅ , -SC ₃ H ₇ , -SC ₄ H ₉ , etc.), -NR'R" (where R' and R" are independently H or alkyl), -OH, -SH, -CN, -N0 ₂ , F, CI, Br, or I. Some examples of optionally substituted alkyl may be alkyl, haloalkyl, perfluoroalkyl, hydroxyalkyl, alkylthiol (i.e. alkyl-SH), -alkyl-CN, etc.

[0023] The term "fluoroalkyl" includes its common meaning in the field and includes alkyl having one or more fluorine substituents. Ci- ₆ F _1-13 fluoroalkyl refers to fluoroalkyl having 1 -6 carbon atoms and 1 -13 fluorine atoms.

[0024] The term "perfluoroalkyl" refers to fluoroalkyl with a formula C _n F _2n +i for a linear or branched structure, e.g., CF ₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , C ₅ Fn , C ₆ F ₁₃ , etc., or C _n F _2n -i for a cyclic structure, e.g., cyclic C ₃ F ₅ , cyclic C ₄ F ₇ , cyclic CsF ₉ , cyclic CeFn , etc. For example, while not intending to be limiting, Ci _-3 perfluoroalkyl refers to CF ₃ , C ₂ F ₅ , and C ₃ F ₇ isomers.

[0025] "Aryl" refers to an aromatic substituent that may be a single ring or multiple rings. The aromatic rings of the aryl group may each and optionally contain heteroatoms, for example, as in pyridine, pyrazine, pyrimidine, carbazolyl or imidazole. The aryl group can be optionally substituted with one or more aryl group substituents which can be the same or different, where "aryl group substituent" includes alkyl, aryl, arylalkyl, hydroxy, alkoxyl, aryloxy, arylalkoxyl, carboxy, -CN, acyl, halo, nitro, alkoxycarbonyl, aryloxycarbonyl, arylalkoxycarbonyl, acyloxyl, acylamino, aroylamino, carbamoyl, alkylhalide, alkylcarbamoyl, dialkylcarbamoyl, arylthio, alkylthio, alkylene, boronic acid, and -NRR', where R and R' can be each independently hydrogen, alkyl, aryl and -alkyl-aryl.

[0026] The term "naphthyl" , includes, but is not limited to the ring systems:

[0027] The term "carbazolyl" refers to the ring system:

which includes, but is not limited to

[0030] The term "benzocarbazolyl" (BCbz) refers to the ring system which is not limited and/or

[0031] The term "phenoxazinyl" refers to:

[0032] The term "phenothiazolyl" refers to:

[0033] The term "phenazolyl" refers to:

[0034] The term "diphenylamine" refers to:

[0035] The term "phenylnaphthylamine" refers to:

[0036] The term "pyrimidinyl" refers to:

[0037] The term "phenylethynyl" refers to:

[0038] Some embodiments include a gas sensing, e.g., oxygen sensing, element comprising a compound represented by Formula 1 :

[0039] With respect to Formula I, FM is H, -CF ₃ , optionally substituted phenyl, optionally substituted phenylethynyl, optionally substituted naphthyl, optionally substituted carbazolyl, optionally substituted pyridinyl, or optionally substituted pyrimidinyl. In some embodiments, F is H. In some embodiments, F is -CF ₃ . In some embodiments, F is CN.

[0040] With respect to Formula I, in some embodiments, FM is optionally substituted phenyl, such as phenyl having 0, 1 , 2, or 3 substituents (e.g. substituents having a molecular weight less than 100 Da, including CH ₃ , C ₂ H ₅ , F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.). In some embodiments, FM is optionally substituted pyndinyl, such as pyndinyl having 0, 1 , or 2 substituents (e.g. substituents having a molecular weight less than 100 Da, including CH ₃ , C ₂ H ₅ , F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.). In some embodiments, F is optionally substituted pyrimidinyl, such as pyrimidinyl having 0 substituents or 1 substituent (e.g. a substituent having a molecular weight less than 100 Da, including CH ₃ , C ₂ H ₅ , F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.). In some embodiments, F is optionally substituted naphthyl, such as naphthyl having 0, 1 , 2, or 3 substituents (e.g. substituents having a molecular weight less than 100 Da, including CH ₃ , C ₂ H ₅ , F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.). In some embodiments, F is optionally substituted carbazolyl, such as carbazolyl having 0, 1 , 2, 3, or 4 substituents (e.g. substituents having a molecular weight less than 200 Da, such as Ci _-6 alkyl, F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , phenyl, etc.). In some embodiments, FM is optionally substituted phenylethynyl, such as phenylethynyl having 0, 1 , 2, or 3 substituents (e.g. substituents having a molecular weight less than 100 Da, including CH ₃ , C2H5, F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.). -CN, -

[0042] With respect to Formula I, R ₂ is -CN or -CF ₃ . [0043] With respect to Formula I, R ₃ is optionally substituted carbazolyl such as carbazolyl having 0, 1 , 2, 3, or 4 substituents (e.g. substituents having a molecular weight less than 300 Da, such as C ₁ - ₁₂ alkyl, such as CH ₃ , C ₂ alkyl, C ₃ alkyl, C ₃ cycloalkyl, C ₄ alkyl, C ₄ cycloalkyl, C ₅ alkyl, C ₅ cycloalkyl, C ₆ alkyl, C ₆ cycloalkyl, etc.; F; CI; Br; CF ₃ ; CN; COH; -CO-alkyl, such as -COCH ₃ , -COC ₂ H ₅ , - COC ₃ H ₇ , -COC ₄ H ₉ , etc; -O-alkyl, such as -OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ , etc.; optionally substituted -CO-phenyl; optionally substituted -O-phenyl; optionally substituted phenyl; optionally substituted diphenylamino; optionally substituted carbazolyl; optionally substituted phenoxazinyl; etc.); optionally substituted phenyl, such as phenyl having 0, 1 , 2, or 3 substituents (e.g. substituents having a molecular weight less than 100 Da, including CH ₃ , C ₂ H ₅ , F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.); or optionally substituted benzocarbazolyl such as benzocarbazolyl having 0, 1 , 2, 3, or 4 substituents (e.g. substituents having a molecular weight less than 300 Da, such as Ci-i ₂ alkyl, such as CH ₃ , C ₂ alkyl, C ₃ alkyl, C ₃ cycloalkyl, C ₄ alkyl, C ₄ cycloalkyl, C ₅ alkyl, C ₅ cycloalkyl, C ₆ alkyl, C ₆ cycloalkyl, etc.; F; CI; Br; CF ₃ ; CN; COH; -CO-alkyl, such as -COCH ₃ , -COC ₂ H ₅ , -COC ₃ H ₇ , -COC ₄ H ₉ , etc; -O-alkyl, such as -OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ , etc.; optionally substituted -CO-phenyl; optionally substituted -O-phenyl; optionally substituted phenyl; optionally substituted diphenylamino; optionally substituted carbazolyl; optionally substituted phenoxazinyl; etc.). In some embodiments, R ₃ is optionally substituted carbazolyl. In some embodiments, R ₃ is optionally substituted benzocarbazolyl.

[0044] In some embodiments, R ₃ is

-11-

[0045] With respect to Formula I, R ₄ is optionally substituted carbazolyl such as carbazolyl having 0, 1 , 2, 3, or 4 substituents (e.g. substituents having a molecular weight less than 300 Da, such as C ₁ - ₁₂ alkyl, such as CH ₃ , C ₂ alkyl, C ₃ alkyl, C ₃ cycloalkyl, C ₄ alkyl, C ₄ cycloalkyl, C ₅ alkyl, C ₅ cycloalkyl, C ₆ alkyl, C ₆ cycloalkyl, etc.; F; CI; Br; CF ₃ ; CN; COH; -CO-alkyl, such as -COCH ₃ , -COC ₂ H ₅ , - COC ₃ H ₇ , -COC ₄ H ₉ , etc; -O-alkyl, such as -OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ , etc.; optionally substituted -CO-phenyl; optionally substituted -O-phenyl; optionally substituted phenyl; optionally substituted diphenylamino; optionally substituted carbazolyl; optionally substituted phenoxazinyl; etc.); optionally substituted phenyl, such as phenyl having 0, 1 , 2, or 3 substituents (e.g. substituents having a molecular weight less than 100 Da, including CH ₃ , C ₂ H ₅ , F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.); or optionally substituted benzocarbazolyl, such as benzocarbazolyl having 0, 1 , 2, 3, or 4 substituents (e.g. substituents having a molecular weight less than 300 Da, such as Ci-i ₂ alkyl, such as CH ₃ , C ₂ alkyl, C ₃ alkyl, C ₃ cycloalkyl, C ₄ alkyl, C ₄ cycloalkyl, C ₅ alkyl, C ₅ cycloalkyl, C ₆ alkyl, C ₆ cycloalkyl, etc.; F; CI; Br; CF ₃ ; CN; COH; -CO-alkyl, such as -COCH ₃ , -COC ₂ H ₅ , -COC ₃ H ₇ , -COC ₄ H ₉ , etc; -O-alkyl, such as -OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ , etc.; optionally substituted -CO-phenyl; optionally substituted -O-phenyl; optionally substituted phenyl; optionally substituted diphenylamino; optionally substituted carbazolyl; optionally substituted phenoxazinyl; etc.). In some embodiments, R ₄ is optionally substituted carbazolyl. In some embodiments, R ₄ is optionally substituted benzocarbazolyl. [0046] In some embodiments, R ₄ is

[0047] With respect to Formula I, R ₅ is optionally substituted carbazolyl, optionally substituted phenyl, or optionally substituted benzocarbazolyl. In some embodiments, R ₅ is optionally substituted carbazolyl, such as carbazolyl having 0, 1 , 2, 3, or 4 substituents (e.g. substituents having a molecular weight less than 300 Da, such as C1-12 alkyl, such as CH ₃ , C2 alkyl, C3 alkyl, C3 cycloalkyl, C ₄ alkyl, C ₄ cycloalkyl, C ₅ alkyl, C ₅ cycloalkyl, C ₆ alkyl, C ₆ cycloalkyl, etc.; F; CI; Br; CF ₃ ; CN; COH; -CO-alkyl, such as -COCH ₃ , -COC ₂ H ₅ , -COC ₃ H ₇ , -COC ₄ H ₉ , etc; -O-alkyl, such as -OCH ₃ , -OC2H5, -OC ₃ H ₇ , -OC ₄ H ₉ , etc.; optionally substituted -CO-phenyl; optionally substituted -O-phenyl; optionally substituted phenyl; optionally substituted diphenylamino; optionally substituted carbazolyl; optionally substituted phenoxazinyl; etc.); optionally substituted phenyl, such as phenyl having 0, 1 , 2, or 3 substituents (e.g. substituents having a molecular weight less than 100 Da, including CH ₃ , C ₂ H ₅ , F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.)

[0048] In some embodiments, R ₅ is optionally substituted phenyl, such as phenyl having 0, 1 , 2, or 3 substituents (e.g. substituents having a molecular weight less than 100 Da, including CH ₃ , C ₂ H ₅ , F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.)

[0049] In some embodiments, R ₅ is optionally substituted benzocarbazolyl, such as benzocarbazolyl having 0, 1 , 2, 3, or 4 substituents (e.g. substituents having a molecular weight less than 300 Da, such as C1-12 alkyl, such as CH ₃ , C ₂ alkyl, C ₃ alkyl, C ₃ cycloalkyl, C ₄ alkyl, C ₄ cycloalkyl, C ₅ alkyl, C ₅ cycloalkyl, C ₆ alkyl, C ₆ cycloalkyl, etc.; F; CI; Br; CF ₃ ; CN; COH; -CO-alkyl, such as -COCH ₃ , -COC ₂ H ₅ , - COC ₃ H ₇ , -COC ₄ H ₉ , etc; -O-alkyl, such as -OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ , etc.; optionally substituted -CO-phenyl; optionally substituted -O-phenyl; optionally substituted phenyl; optionally substituted diphenylamino; optionally substituted carbazolyl; optionally substituted phenoxazinyl; etc.)

[0050] In some embodiments, R ₅ and R ₆ is

[0051] With respect to Formula I, R ₆ is optionally substituted carbazolyl, optionally substituted phenyl, or optionally substituted benzocarbazolyl.

[0052] In some embodiments, R ₆ is optionally substituted carbazolyl, such as carbazolyl having 0, 1 , 2, 3, or 4 substituents (e.g. substituents having a molecular weight less than 300 Da, such as C1-12 alkyl, such as CH ₃ , C ₂ alkyl, C ₃ alkyl, C ₃ cycloalkyl, C ₄ alkyl, C ₄ cycloalkyl, C ₅ alkyl, C ₅ cycloalkyl, C ₆ alkyl, C ₆ cycloalkyl, etc.; F; CI; Br; CF ₃ ; CN; COH; -CO-alkyl, such as -COCH ₃ , -COC ₂ H ₅ , - COC ₃ H ₇ , -COC ₄ H ₉ , etc; -O-alkyl, such as -OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ , etc.; optionally substituted -CO-phenyl; optionally substituted -O-phenyl; optionally substituted phenyl; optionally substituted diphenylamino; optionally substituted carbazolyl; optionally substituted phenoxazinyl; etc.)

[0053] In some embodiments, R ₆ is optionally substituted phenyl, such as phenyl having 0, 1 , 2, or 3 substituents (e.g. substituents having a molecular weight less than 100 Da, including CH ₃ , C ₂ H ₅ , F, CI, Br, CF ₃ , CN, COH, COCH ₃ , OCH ₃ , etc.).

[0054] In some embodiments, R ₆ is optionally substituted benzocarbazolyl, such as benzocarbazolyl having 0, 1 , 2, 3, or 4 substituents (e.g. substituents having a molecular weight less than 300 Da, such as C1-12 alkyl, such as CH ₃ , C2 alkyl, C ₃ alkyl, C ₃ cycloalkyl, C ₄ alkyl, C ₄ cycloalkyl, C ₅ alkyl, C ₅ cycloalkyl, C ₆ alkyl, C ₆ cycloalkyl, etc.; F; CI; Br; CF ₃ ; CN; COH; -CO-alkyl, such as -COCH ₃ , -COC ₂ H ₅ , - COC ₃ H ₇ , -COC ₄ H ₉ , etc; -O-alkyl, such as -OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ , etc.; optionally substituted -CO-phenyl; optionally substituted -O-phenyl; optionally substituted phenyl; optionally substituted diphenylamino; optionally substituted carbazolyl; optionally substituted phenoxazinyl; etc.)

[0055] In some embodiments, R ₅ and R ₆ are independently

[0056] In some embodiments, R ₃ , R ₄ , R ₅ and R ₆ are the same. In some embodiments, R ₃ and R ₄ are the same. In some embodiments R ₅ and R ₆ are the same.

[0057] In some embodiments, the compound can be represented by Formula 2:

wherein R ₇ can independently be an optionally substituted arylene group, an optionally substituted carbazolyl group; and R ₈ can be hydrogen, an alkyl group, an optionally substituted phenyl and/or an optionally substituted carbazolyl.

[0058] In some embodiments, R ₇ can be :

[0059] In some embodiments, R ₈ can be:

[0060] In some embodiments, the compound can be represented by Formula 3:

Formula 3,

wherein R ₉ is an optionally substituted aryl or an optionally substituted heteroaryl group; and wherein, R ₁₀ is an electron donor heteroaryl group, e.g., an optionally substituted heteroaryl. In some embodiments, R ₉ can be an electron acceptor group. In some embodiments, R ₉ can be an electron acceptor aryl group and/or an electron acceptor heteroaryl group. In some embodiments, R ₉ can be selected from an optionally substituted phenyl, optionally substituted phenylacetylene, optionally substituted naphthalene, optionally substituted acenaphthylene, optionally substituted pyridinyl and/or optionally substituted pyrimidinyl. In some embodiments, R ₁₀ can be an optionally substituted carbazolyl, an optionally substituted benzocarbazolyl, an optionally substituted phenoxazolyl, an optionally substituted phenothiazolyl and/or an optionally substituted phenazolyl. [0061] In some embodiments, the compound can be represented by Formula 4:

Formula 4

wherein Rn can be an optionally substituted aryl and/or an optionally substituted heteroaryl; and wherein Cbz can be an optionally substituted carbazolyl.

[0062] In some embodiments, the compound can be represented by Formula 5:

Formula 5,

wherein Ri ₂ can be an optionally substituted aryl and/or an optionally substituted heteroaryl; and wherein BCbz can be an optionally substituted benzocarbazolyl.

[0063] In some embodiments, a compound for use in emissive elements of organic light emitting devices, the compound being represented by Formula 6:

Formula 6

wherein R ₁₃ can be an optionally substituted phenyl, optionally substituted phenylacetylene, optionally substituted naphthalene, and/or optionally substituted acenaphthylene. [0064] In some embodiments, the compound can be represented by Formula 7:

Formula 7

wherein R ₁₄ is selected from is selected from optionally substituted phenyl, optionally substituted phenylacetylene, optionally substituted naphthalene, and optionally substituted acenaphthylene. In some embodiments, the compound is an emissive compound. In some embodiments, the compound can be used in emissive elements of organic light emitting devices.

[0065] In some embodiments, R ₉ , Rn , R ₁₂ , R13 and/or R ₁₄ can be an optionally substituted aryl and/or heteroaryl. In some embodiments, R ₉ , Rn , R ₁₂ , R13 and/or R ₁₄ can be an unsubstituted aryl. In some embodiments, R ₉ , Rn , R ₁₂ , R13 and/or R ₁₄ can be a mono-substituted aryl. In some embodiments, R ₉ , Rn , R ₁₂ , R13 and/or R ₁₄ can be di-substituted aryl. In some embodiments, R ₉ , Rn , R ₁₂ , R ₁₃ and/or R ₁₄ can be an unsubstituted heteroaryl. In some embodiments, R ₉ , Rn , R ₁₂ , R ₁₃ and/or R ₁₄ can be a mono-substituted heteroaryl. In some embodiments, R ₉ , R11 , R12, Ri 3 and/or R ₁₄ can be a di-substituted heteroaryl. In some embodiments, R9, R11 , R12, Ri3 and/or R ₁₄ can bean optionally substituted phenyl, optionally substituted phenylacetylene, optionally substituted naphthalene, optionally substituted acenaphthylene, an optionally substituted pyrimidinyl and/or an optionally substituted pyridinyl. In some embodiments, the optionally substituted aryl and/or heteroaryl can be:

[0066] In some embodiments, Rn, and/or an optionally substituted electron donor heteroaryl, e.g., Cbz, can be

[0067] In some embodiments, Rn and/or an optionally substituted BCbz can be selected from:

[0068] Some embodiments provide a compound represented by Formula

Formula 8,

wherein R ₁₅ is an electron acceptor compound selected from an optionally substituted phenyl, optionally substituted pyridinyl and optionally substituted pyrimidinyl; and wherein, R ₁₆ is an electron donor compound selected from an optionally substituted carbazolyl, an optionally substituted benzocarbazolyl, an optionally substituted phenoxazolyl, an optionally substituted phenothiazolyl and an optionally substituted phenazolyl.

[0069] Some embodiments include a compound selected from optionally (4'r,6'r)-5'-(4-cyanophenyl)-4',6'-bis(3,6-diphenyl-9H-carba zol-9-yl)-[1 , 1 ':3',1 "- terphenyl]-2',4,4"-tricarbonitrile (Emitting Compound 1 [EM-25]), (4'R,6'R)-4',6'- bis(7H-benzo[c]carbazol-7-yl)-5'-(4-cyanophenyl)-[1 , 1 ':3', 1 "-terphenyl]-2',4,4"- tricarbonitrile [EM-26]), (4'R,6'R)-4',6'-bis(5H-benzo[b]carbazol-5-yl)-5'-(4- cyanophenyl)-[1 ,r:3',1 "-terphenyl]-2',4,4"-tricarbonitrile, (4'R,6'R)-4',6'-bis(7H- benzo[c]carbazol-7-yl)-4,4"-bis(trifluoromethyl)-5'-(4-(trif luoromethyl)phenyl)- [1 , 1 ':3', 1 "-terphenyl]-2'-carbonitrile, (4'R,6'R)-4',6'-bis(5H-benzo[b]carbazol-5-yl)-4,4"- bis(trifluoromethyl)-5'-(4-(trifluoromethyl)phenyl)-[1 , 1 ':3', 1 "-terphenyl]-2'-carbonitrile, (S)-5'-(4-cyanophenyl)-4',6'-bis(3-(diphenylamino)-9H-carbaz ol-9-yl)-[1 , 1 ':3', 1 "- terphenyl]-2',4,4"-tricarbonitrile, (S)-3,5-bis(6-cyanopyridin-3-yl)-2,6-bis(3- (diphenylamino)-9H-carbazol-9-yl)-[1 , 1 '-biphenyl]-4,4'-dicarbonitrile, (4'r,6'R)-4',6'- bis(9'H-[9,3':6',9"-tercarbazol]-9'-yl)-5'-(4-cyanophenyl)-[ 1 , 1 ':3', 1 "-terphenyl]-2',4,4"- tricarbonitrile (EM-27), (S)-4',6'-bis(3-(10H-phenoxazin-10-yl)-9H-carbazol-9-yl)-5'- (4- cyanophenyl)-[1 , 1 ':3',1 "-terphenyl]-2',4,4"-tricarbonitnle, (S)-5,5',5"-(2,4-bis(3-(10H- phenoxazin-10-yl)-9H-carbazol-9-yl)-6-cyanobenzene-1 ,3,5-triyl)tripicolinonitnle, and (s)-4',6'-bis(3,6-bis(diphenylamino)-9H-carbazol-9-yl)-5'-(4 -cyanophenyl)-[1 , 1 ':3', 1 "- terphenyl]-2',4,4"-thcarbonitrile].

[0070] In some embodiments, the compound can be at least one of :

-24-

-25-

-26-

-27-

-28-

(EM-40), and/or

[0071] In some embodiments, the chemical compounds can be at least those TADF compounds described in United States Provisional Patent Application Nos. 61/821 ,597, filed May 9, 2013; 61/917,876, filed December 18, 2013 [PCT/US2014/037572, filed 09-May-2014, WO2014/183080, published on November 13, 2014, Appendix A]; 61/897,657, filed October 30, 2013 [PCT/US2014/63207, filed October 30, 2014, Appendix B], and/or 62/013,416, filed June 17, 2014 [Appendix C], which are incorporated by reference in their entireties for their disclosure of TADF compounds and attached as appendices A, B and C, respectively. In some embodiments, the chemical compounds can be at least those having a AS1 - T1 < 0.1 .

[0072] In some embodiments, a method of detecting a gas, e.g., oxygen, in a sample is provided, the method comprising contacting the sample with a TADF compound described herein; and detecting the presence or absence of colored emissions from the sample, wherein the presence of colored emissions indicates the presence of an analyte in the sample. In some embodiments, the analyte can be a triplet state quencher (TSQ). In some embodiments, the analyte can be 0 ₂ . In some embodiments, wherein the compound can be EM-8, and the colored emission can be light blue (emissive λ about 500 nm). In some embodiments, wherein the compound can be EM-8, the analyte can be 0 ₂ . In some embodiments, the method further comprises measuring the amount of blue emission in the sample and correlating the amount of blue emission from the sample with a concentration of the oxygen in the sample.

[0073] An oxygen sensor element comprising a compound described herein may be configured to detect about 0.1 %, about 0.2%, about 0.5%, about 1 %, about 2%, about 8%, or about 12% or higher 0 ₂ by volume in an atmosphere that comes into contact with the oxygen sensor element. For example, an oxygen sensor may configured to change color, or otherwise indicate, when an atmosphere in contact with the oxygen sensor, has an oxygen content that increases so it reaches 0.1 % 0 ₂ by volume to alert the user that the contents may no longer be good.

[0074] The oxygen sensor may be within a packaging layer, such as a wrapper or film. The packaging layer may act as a barrier to the passage of oxygen. For example, the packaging layer may impair the passage of oxygen through the packaging layer. Thus, an oxygen sensor inside the packaging layer may detect when the packaging layer fails by detecting an increase in oxygen content within the packaging.

[0075] In some embodiments, the sample can be contacted with a coated substrate comprising the chemical compound. In some embodiments, the sample can be contacted with a porous substrate and the chemical compound.

[0076] In some embodiments, the compounds described herein can have a first vibrational or energy state having a first color and a second vibrational or energy state having a second color. In some embodiments, the compounds can have a reversible color change from the first energy state to the second energy state. The term color includes no color or clear.

[0077] As shown in FIG. 1 , the excitation/irradiation of a compound, e.g., EM-8, can change the energy state or level of the compound from a ground state energy level (S ₀ ) to an unstable excited state energy level (Si). The excited compound can return to the ground state energy level upon releasing a photon. The excited compound could also non-radiatively pass to a triplet state, or conversely a triplet transitions to a singlet, that process is known as intersystem crossing (ISC). The probability of ISC occurring can be more favorable when the vibrational/energy states/levels (Si , Ti) of the two excited states overlap and/or when the differences between the vibrational/energy states/levels of the two excited states are minimal, since little or no energy must be gained or lost in the transition.

[0078] The S1 and T1 values can be determined by dissolving a sample, e.g., 2 mg, in 1 ml_ of 2-methyltetrahydrofuran (2-MeTHF) and transferring the resulting solution into a quartz tube. The quartz tube containing the sample can then be frozen (77K) by liquid nitrogen prior to measurement. Singlet (S1 ) energy can be determined from the identified first fluorescent emission peak wavelength (nm) and the triplet (Ti) energy can be determined from the identified first phosphorescent emission peak wavelength (nm) measured at 77K, using Fluoromax-3 spectrophotometer (Horiba Instruments, Irvine CA, USA) and then converted into eV (eV = emission peak wavelength (λ) / 1240).

[0079] In some embodiments, Δ S1 -T1 can be less than 0.5, 0.25, 0.1 , 0.05, and /or 0.01 eV, facilitating the ISC between the singlet excited state (S1 ) and the triplet state (T1 ). See Table 1 :

Table 1

[0080] In some embodiments, in the absence of a triplet state quenching gas, e.g., 0 ₂ , the excited compound, e.g., excited EM-8, singlet state returns to the ground state and releases the previously absorbed energy as light. This light is perceived as a color tinge imparted to the solution or compound, e.g., for EM-8, the color can be a light blue (emissive λ = about 500 nm). In some embodiments, it is believed that the presence of 0 ₂ ³ (oxygen triplet) quenches or absorbs the triplet state energy off the chromophore, e.g., EM-8, without returning to the ground state and/or without emitting light. In some embodiments, the triplet state quenching (TSQ) can be effected by the presence of oxygen. In some embodiments, the 0 ₂ % present in the atmosphere or in contact with the chromophore sufficient to effect the quenching can be at least 0.1 %, 0.2%, 0.5%, 1 .0%, 2.0%, 8%, and/or 12% 0 ₂ in the contacting atmosphere. The chromophore or material, upon being exposed to TSQ compound, therefore appears substantially colorless or clear. In some embodiments, the chromophore can reversibly change color, that is, removal of the TSQ gas will return the color to the chromophore solution/composite. In some embodiments, the chromophore can be a compound that has a first and a second coloration depending upon the singlet, triplet and/or ground state. In some embodiments, the chromophore emits a colored light due to the absence of a triplet state quenching material in contact or communication with the chromophore. In some embodiments, the chromophore does not emit a colored light, e.g., it is colorless, in the presence of a triplet state quenching material, e.g., 0 ₂ .

[0081] In some embodiments, the device can comprise an optical sensor, comprising an indicator system. In some embodiments, the indicator system can comprise a compound that exists in at least first and second different forms depending on a concentration of an analyte, wherein the different forms can be distinguished based on their respective first and second emissions at a specified wavelength. In some embodiments, the indicator system can comprise a compound that exists in at least first and second different forms depending on a concentration of an analyte, wherein the different forms can be distinguished based on their respective first and second photonic emissions. In some embodiment, the first and second photonic emissions are characterized by first and second light intensities. In some embodiments, the binding or presence of a triplet state quencher causes an apparent optical change in the apparent emission by the chromophore related to a concentration of the analyte.

[0082] Exposing the sample to a compound that can be a triplet state quencher and an analyte, an increase in the emission has been observed, because, it is believed, the compounds shift from a first vibrational and/or energy state to a second vibrational and/or energy state with or without a concomitant photon/light emission. At higher analyte concentrations, embodiments of the compounds of described herein can provide triplet quenching without discernible visual emissions of described wavelengths (Table 1 ). At below threshold levels of analyte concentrations, the triplet state quenching may not occur, possibly allowing excited singlet to ground state transition, with its photon emission. Since the presence or absence of the TSQ can enable the non-emission or emission of a photon upon return to the ground state energy level, the current sensor can provide reversible indication of the analyte presence or absence.

[0083] In some embodiments, the sensor can be a colorimetric sensor. In some embodiments the sensor can comprises gas sensor tubes. In some embodiments, the gas detector tubes may be used to determine the concentration of at least oxygen gas in a sample gas. The gas detector tubes can comprise any or all of the chemical compounds described herein within a transparent tube. In some embodiments, the gas detector tubes comprise a porous solid with pathways that allow gas to flow through the porous solid from an inlet of the gas detector tube to an outlet of the gas detector tube or the chemical reagent can be on the surface of a porous solid substrate. The chemical compound/the material within the tube can change color when the compound is placed in contact with the chemical reagent, e.g., triplet state quenching material ("colorimetric reaction"), typically the chemical reagent and the target gases will react resulting in the color change. As a sample passes through the gas detector tube, the target gases are involved in the colorimetric reaction with the chemical reagent until the target gases are depleted from the sampled gas. Many reagents for use in gas detector tubes are known and applicable to embodiments of the gas detector tubes. A sample is typically drawn through the gas detector tubes by a sampling pump. Common sample pumps include hand-held piston pumps or bellows pump that are capable of accurately and repeatedly drawing a known volume of air.

[0084] Embodiments of the gas detector tubes of the invention may be read either electronically by an electronic gas detector tube reader or visually by a user by a simple comparison of color scales.

[0085] In some embodiments, the colorimetric sensor can comprise gas sensor coated substrates. In some embodiments, the gas sensor coated substrates may be used to determine the concentration of at least oxygen gas in a sample gas. The gas detector coated substrates can typically comprise a matrix and any or all of the chemical compounds described disposed within the matrix. In some embodiments, the coated substrate can be woven material (natural or manufactured fabrics), non-woven material (e.g., glass fiber, paper, etc.). In some embodiments, the matrix can comprise a substantially transparent polymer. In some embodiments, the substantially transparent polymer can be selected from poly(methylmethacrylate) (PMMA), polyethylene (PE), polyethylene terephthalate (PET), vinylidene chloride and/or polycarbonate (PC). In some embodiments the polyethylene film can be low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and/or high density polyethylene (HDPE). In some embodiments, the density of the PE can be between 0.900, 0.910, 0.920, 0.930 gm/cm ³ to about 0.94, 0.95, 0.96, 0.97, 0.98 gm/cm ³ or any combination the aforementioned densities.

[0086] In some embodiments, a detector, e.g., a photodetector, can be used to detect the fluorescent emission and in some embodiments, may be linked to an electronic control for analysis. Optical filters can be placed between the sensor and the detector for wavelength selection. Other optical components may also be utilized, e.g., mirrors, collimating and/or focusing lenses, beam splitters, etc. Optical fibers can be used to deliver selected wavelengths to the sensor and to deliver the fluorescence emission from the sensor to the detector. The light source and the detector may be controlled by electronic control and/or the outputs from the photodetectors can be analyzed by additional electronics, e.g., a computer.

[0087] In some embodiments, a film can be used to detect the presence of oxygen. In some embodiments, the film can comprise the compounds described herein. In some embodiments, the film further comprises a substantially transparent polymer. In some embodiments, the substantially transparent polymer can be selected from poly(methylmethacrylate) (PMMA), polyethylene (PE), polyethylene terephthalate (PET), vinylidene chloride and/or polycarbonate (PC). In some embodiments the polyethylene film can be low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and/or high density polyethylene (HDPE). In some embodiments, the density of the PE can be between 0.900, 0.910, 0.920, 0.930 gm/cm ³ to about 0.94, 0.95, 0.96, 0.97, 0.98 gm/cm ³ or any combination the aforementioned densities.

[0088] As shown in FIG. 2, in some embodiments, the film 10 can comprise a first layer 120 and second layer 122, the first layer comprising the any of the compounds described herein. In some embodiments, as shown in FIG. 2, a first layer 120 can be disposed adjacent to a second layer 122. The plural layer film 1 10 can define a cavity 124 therein and/or surround a target material, the first layer disposed within the interior of the defined cavity, such that presence of oxygen, e.g., passing through the first and or second layer or generated within the cavity 124, contacts the first layer and colorimetrically shifts the color from a first color to a second color. In some embodiments, the first color can be about

[0089] In some embodiments, film can comprise a first layer 120 and second layer 122, the first layer comprising any of the compounds described herein. In some embodiments, as shown in FIGS. 3 and 5, a first layer 120 can be disposed between or adjacent to a second layer 122 and/or third layer 126. The plural layer film 1 10 can define a cavity 124 therein and/or surround a target material, the first layer disposed within the interior of the defined cavity, such that presence of oxygen, e.g., passing through the second and or third layers or generated within the cavity 124, contacts the first layer and colorimetrically shifts the color from a first color to a second color.

Embodiments

Embodiment 1. An oxygen sensor element comprising an emissive compound represented by Formula 1 :

wherein F is H, -CF ₃ , optionally substituted phenyl, optionally substituted phenylethynyl, optionally substituted naphthyl, optionally substituted carbazolyl, optionally substituted pyridinyl, or optionally substituted pyrimidinyl; R ₂ is -CN or -CF _3;

R ₃ and R ₄ are independently optionally substituted carbazolyl, optionally substituted phenyl, or optionally substituted benzocarbazolyl; and

R ₅ and R ₆ are independently optionally substituted carbazolyl, optionally substituted phenyl, or optionally substituted benzocarbazolyl.

Embodiment 2. The oxygen sensor element of embodiment 1 , wherein R^ is optionally substituted phenyl.

Embodiment 3. The oxygen sensor element of embodiment 1 , wherein R^ is H.

Embodiment 4. The oxygen sensor element of embodiment 1 , wherein R^ is optionally substituted pyridinyl.

Embodiment 5. The oxygen sensor element of embodiment 1 , wherein R^ is optionally substituted pyrimidinyl.

Embodiment 6. The oxygen sensor element of embodiment 1 , wherein Ri is optionally substituted naphthyl.

Embodiment 7. The oxygen sensor element of embodiment 1 , wherein R^ is optionally substituted carbazolyl.

Embodiment 8. The oxygen sensor element of embodiment 1 , wherein R^ is optionally substituted phenylethynyl.

Embodiment 9. The oxygen sensor element of embodiment 1 , wherein R^ is -CF ₃ .

Embodiment 10. The oxygen sensor element of embodiment 1 , wherein R^ is CN.

Embodiment 11. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein R ₂ is -CN.

Embodiment 12. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein R ₂ is -CF ₃ .

Embodiment 13. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or 12, wherein R ₃ is optionally substituted carbazolyl.

Embodiment 14. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or 12, wherein R ₃ is optionally substituted benzocarbazolyl.

Embodiment 15. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, or 14, wherein R ₄ is optionally substituted carbazolyl. Embodiment 16. The oxygen sensor element of embodiment 13, wherein R ₄ is optionally substituted carbazolyl.

Embodiment 17. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, or 13, wherein R ₄ is optionally substituted benzocarbazolyl.

Embodiment 18. The oxygen sensor element of embodiment 14, wherein R ₄ is optionally substituted benzocarbazolyl.

Embodiment 19. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 17, or 18, wherein R ₅ is optionally substituted carbazolyl.

Embodiment 20. The oxygen sensor element of embodiment 16, wherein R ₅ is optionally substituted carbazolyl.

Embodiment 21. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, or 17, wherein R ₅ is optionally substituted phenyl.

Embodiment 22. The oxygen sensor element of embodiment 18, wherein R ₅ is optionally substituted phenyl.

Embodiment 23. The oxygen sensor element of embodiment 16, wherein R ₅ is optionally substituted phenyl.

Embodiment 24. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, or 17, wherein R ₅ is optionally substituted benzocarbazolyl.

Embodiment 25. The oxygen sensor element of embodiment 18, wherein R ₅ is optionally substituted benzocarbazolyl.

Embodiment 26. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 21 , 22, 23, 24, or 25, wherein R ₆ is optionally substituted carbazolyl.

Embodiment 27. The oxygen sensor element of embodiment 19, wherein R ₆ is optionally substituted carbazolyl.

Embodiment 28. The oxygen sensor element of embodiment 20, wherein R ₆ is optionally substituted carbazolyl.

Embodiment 29. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 19, 20, 21 , 24, or 25, wherein R ₆ is optionally substituted phenyl. Embodiment 30. The oxygen sensor element of embodiment 18, wherein R ₆ is optionally substituted phenyl.

Embodiment 31. The oxygen sensor element of embodiment 22, wherein R ₆ is optionally substituted phenyl.

Embodiment 32. The oxygen sensor element of embodiment 23, wherein R ₆ is optionally substituted phenyl.

Embodiment 33. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, or 24, wherein R ₆ is optionally substituted benzocarbazolyl.

Embodiment 34. The oxygen sensor element of embodiment 18Error! Reference source not found., wherein R ₆ is optionally substituted benzocarbazolyl.

Embodiment 35. The oxygen sensor element of embodiment 25, wherein R ₆ is optionally substituted benzocarbazolyl.

Embodiment 36. The oxygen sensor element of embodiment 1 wherein Ri i

Embodiment 37. The oxygen sensor element of embodiment 1 wherein the emissive compound is:

-40-

-42-

-44-

Embodiment 38. The oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, or 37, which is configured to detect an oxygen level of 0.5% by volume or less in an atmosphere that comes into contact with the oxygen sensor element.

Embodiment 39. A package containing the oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, or 38, wherein the oxygen sensor element is within a packaging layer, wherein the packaging layer is a barrier to the passage of oxygen through the barrier to come into contact with the oxygen sensor element.

Embodiment 40. A method of detecting an oxygen-containing analyte in a sample comprising contacting the sample with the oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, or 39; and detecting the presence or absence of blue emissions from the sample, wherein the presence of blue emissions indicates the absence of oxygen in the sample. Embodiment 41. The method of embodiment 40, further comprising measuring the amount of blue emission in the sample and correlating the amount of blue emission from the sample with a concentration of the oxygen in the sample.

Embodiment 42. A method for determining the presence of oxygen in a sealed cavity, the method comprising:

a. forming a first layer, the first layer comprising the oxygen sensor element of embodiment 1 , wherein the compound has a first and second form, the first and second chemical forms having different visual characteristics;

b. forming second layer adjacent to the first layer and isolating the first layer from contact with the ambient environment, wherein the presence of oxygen contacting the first layer to a sufficient level to effect a color change of the first layer.

Embodiment 43. A colorimetric indicating film comprising a first layer, the first layer comprising the oxygen sensor element of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, or 38.

Embodiment 44. The film of embodiment 43, wherein the film further comprises polymethylmethacrylate.

Embodiment 45. The film of embodiment 44, further comprising a second layer, wherein the first and second layers are adjacent to each other, and wherein the first and second layers define an internal cavity therein, and wherein the first layer is a first color in an oxygen deficient atmosphere and a second color in an oxygen present atmosphere.

[0090] It has been discovered that embodiments of elements described herein have promise to provide 0 ₂ detection described concentrations. These benefits are further shown by the following examples, which are intended to be illustrative of the embodiments of the disclosure, but are not intended to limit the scope or underlying principles in any way.

EXAMPLES

Example 1 - Synthesis of Emissive Materials 4-cyanophenylboronic acid

[0091 ] 2,3,5,6-tetraf luro-4-(4'-cyanophenyl)-benzonitrile (Compound

1 ): A mixture of 4-cyanophenylboronic acid (1 .83 g, 8 mmol), 4-bromo-2, 3,5,6- tetrafluorobenzonitrile (1 .0 g, 3.9 mmol), Pd ₂ (dba) ₃ (0.18 g, 0.2 mmol), SPhos (0.16 g, 0.4 mmol) and K ₃ P0 ₄ (2.0 g, 8.7 mmol) in toluene (40 mL) was degassed and heated at about 120 °C for about 16 hours. After cooled to room temperature, the mixture was filtered and washed with toluene. The filtrate was loaded on silica gel and purified by flash column using eluents of dichloromethane/hexanes (10% to 40%). The desired fraction was collected and concentrated to give a white solid (Compound 1 ) (0.367 g, in 34% yield).

[0092] EM-8: To a solution of 2,3,5,6-tetrafluro-4-(4'-cyanophenyl)- benzonitrile (Compound 1 ) (0.277 g, 1 mmol), 9H-carbazole (0.835 g, 5 mmol) in THF (25 mL) was added sodium hydride (60% in mineral oil, 0.2 g, 5 mmol) at about 0 °C and stirred for about 30 min. The mixture was heated at about 60 °C for about 16 hours, then worked up with dichloromethane/brine, dried over Na ₂ S0 ₄ , loaded on silica gel and purified by flash column using eluents of dichloromethane/hexanes (10% to 60%). The desired fraction was collected and concentrated to give a light yellow solid (EM-8) (0.41 g, in 47% yield). Confirmed by LCMS (APCI): Calcd for C62H37N6 (M+H): 865; Found: 865.

Examples 2-27

[0093] The various compounds were prepared in the manner as described in the respective paragraphs of appendix 1 (WO Publication WO2014/183080 [application PCT/US2014/037572], published on November 13, 2014; PCT application filed 09-May-2014 PCT/US2014/63207, filed October 30, 2014], and United States Provisional Application 62/013,416, filed June 17, 2014 as set forth in Table 2, below.

TABLE 2

Compound Appendix Paragraph

EM-16 Appendix A [0141 ]

EM-17 Appendix A [0142]

EM-13 Appendix A [0134], [0135], [0136]

EM-27 Appendix C [0092]

EM-10 Appendix A [0125], [0126], [0127],

[0128]

EM-21 Appendix A [0152], [0153], [0151 ]

EM-23 Appendix A [0148], [0149], [0150]

EM-22 Appendix A [0147]

[0094] Photoluminescence (PL) spectra were recorded on a FluoroMax-3 fluorescence spectrophotometer (Horiba Jobin Yvon, Edison, New Jersey, USA) . 2- Methyltetrahydrofuran (2-MeTHF) (Aldrich, spectroscopic grade) was used as received. 2 M (2mg of sample/1 ml_ of 2-MeTHF) was prepared and then transferred to quartz tube prior to measurement. Then, the sample was frozen by liquid nitrogen at 77K. Fluorescent emission spectrum was recorded and the highest-energy vibronic band was determined to calculate singlet (S1 ) energy level. Phosphorescent emission spectrum was recorded and the highest-energy vibronic band was determined to calculate triplet (T1 ) energy level. The results are shown in Table 1 .

Emission determination

[0095] 0.0025 gm of EM-8 prepared as described in Example 1 above, was dissolved in 10 ml of toluene at room temperature under an ambient atmosphere (EM-8 air). After 1 ml of toluene without the EM-8 air was blanked in a 3 ml quartz cuvette and placed in a HORIBA Jobin Yvon Fluorometer (HORIBA Instruments, Irvine, CA, USA), 1 ml EM-8 air / toluene solution was placed in a 3 ml quartz cuvette, placed in a HORIBA Jobin Yvon Fluorometer and the emission of the EM-8 air solution was determined over 350 nm to about 650 nm visible light. The results are shown in FIG. 7.

[0096] Another sample (EM-8 N ₂ ) was prepared in a manner similar to that described immediately above, except that the sample after preparation under ambient air conditions, the sample was degassed under N ₂ gas for about 10 minutes. A visual comparison of the samples showed that the EM-8 N ₂ sample had a blue tinge while the EM-8 air sample was clear and colorless. A 1 ml EM-8 air solution sample was tested in the same manner described above. The results are shown in FIG.7. The EM-8 N ₂ sample had an emission of about 1 10000, while the EM-8 air sample had an emission of less than 2000.

Fabrication of oxygen sensing film:

[0097] A solution of EM-8 (0.5mg) in toluene (1 ml_) was added to 20 %wt poly(methyl methacrylate) (PMMA) in toluene (10ml_). The solution was stirred for 2 hours in air, then spin coated on a commercially available glass slide (about 1 x 3 inches) to form a thin film (50 urn thickness).

[0098] The coated glass slide were placed inside a sealed glass container (250 ml), and the sealed glass container was filled with 12% 0 ₂ , 8% 0 ₂ , 2% 0 ₂ , 1 % 0 ₂ , 0.5% 0 ₂ , N ₂ only, respectively. The emission of the respective containers was determined on a HORIBA Jobin Yvon Fluorometer for each coated glass slide between about 350 nm to about 600 nm visible light. The results are shown in FIG. 8. The emissive intensity under N ₂ (no 0 ₂ ) l ₀ /l emissive intensity of slides under various oxygen atmospheres described above were determined and plotted as shown in FIG. 9, which shows a substantially linear functional relationship between l ₀ /l from about 1 % 0 ₂ to 12% 0 ₂ .

[0099] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. [00100] The terms "a," "an," "the" and similar referents used in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of any claim. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[00101] Groupings of alternative elements or embodiments disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability

[00102] Certain embodiments are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, the claims include all modifications and equivalents of the subject matter recited in the claims as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is contemplated unless otherwise indicated herein or otherwise clearly contradicted by context.

[00103] In closing, it is to be understood that the embodiments disclosed herein are illustrative of the principles of the claims. Other modifications that may be employed are within the scope of the claims. Thus, by way of example, but not of limitation, alternative embodiments may be utilized in accordance with the teachings herein. Accordingly, the claims are not limited to embodiments precisely as shown and described.