Organic electroluminescent materials and devices

A composition including a first compound is disclosed, wherein the first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature; wherein the first compound has at least one aromatic ring and at least one substituent R; wherein each of the at least one R is an organic group having at least one X—F bond; wherein each X is independently selected from the group consisting of Si, and Ge; and wherein each of the at least one R is directly bonded to one of the aromatic rings.

PARTIES TO A JOINT RESEARCH AGREEMENT

FIELD OF THE INVENTION

The present invention relates to compounds for use as emitters and devices, such as organic light emitting diodes, including the same.

BACKGROUND

SUMMARY OF THE INVENTION

According to an aspect of the present disclosure, a composition comprising a first compound is disclosed. The first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature; wherein the first compound has at least one aromatic ring and at least one substituent R; wherein each of the at least one R is an organic group having at least one X—F bond; wherein each X is independently selected from the group consisting of Si, and Ge; and wherein each of the at least one R is directly bonded to one of the aromatic rings.

According to another aspect of the present disclosure, a first organic light emitting device is disclosed. The first organic light emitting device can include an anode, an organic layer, disposed between the anode and the cathode. The organic layer comprises a first compound;

wherein the first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature;

wherein the first compound has at least one aromatic ring and at least one substituent R;

wherein each of the at least one R is an organic group having at least one X—F bond;

wherein each X is independently selected from the group consisting of Si, and Ge; and

wherein each of the at least one R is directly bonded to one of the aromatic rings.

According to yet another aspect of the present disclosure, a formulation comprising the first compound is disclosed.

DETAILED DESCRIPTION

The term “halo,” “halogen,” or “halide” as used herein includes fluorine, chlorine, bromine, and iodine.

The term “alkyl” as used herein contemplates both straight and branched chain alkyl radicals. Preferred alkyl groups are those containing from one to fifteen carbon atoms and includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and the like. Additionally, the alkyl group may be optionally substituted.

The term “cycloalkyl” as used herein contemplates cyclic alkyl radicals. Preferred cycloalkyl groups are those containing 3 to 7 carbon atoms and includes cyclopropyl, cyclopentyl, cyclohexyl, and the like. Additionally, the cycloalkyl group may be optionally substituted.

The term “alkenyl” as used herein contemplates both straight and branched chain alkene radicals. Preferred alkenyl groups are those containing two to fifteen carbon atoms. Additionally, the alkenyl group may be optionally substituted.

The term “alkynyl” as used herein contemplates both straight and branched chain alkyne radicals. Preferred alkynyl groups are those containing two to fifteen carbon atoms. Additionally, the alkynyl group may be optionally substituted.

The terms “aralkyl” or “arylalkyl” as used herein are used interchangeably and contemplate an alkyl group that has as a substituent an aromatic group. Additionally, the aralkyl group may be optionally substituted.

The term “heterocyclic group” as used herein contemplates aromatic and non-aromatic cyclic radicals. Hetero-aromatic cyclic radicals also means heteroaryl. Preferred hetero-non-aromatic cyclic groups are those containing 3 or 7 ring atoms which includes at least one hetero atom, and includes cyclic amines such as morpholino, piperdino, pyrrolidino, and the like, and cyclic ethers, such as tetrahydrofuran, tetrahydropyran, and the like. Additionally, the heterocyclic group may be optionally substituted.

The term “aryl” or “aromatic group” as used herein contemplates single-ring groups and polycyclic ring systems. The polycyclic rings may have two or more rings in which two carbons are common to two adjoining rings (the rings are “fused”) wherein at least one of the rings is aromatic, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryl, heterocycles, and/or heteroaryls. Additionally, the aryl group may be optionally substituted.

The term “heteroaryl” as used herein contemplates single-ring hetero-aromatic groups that may include from one to three heteroatoms, for example, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, pyrazole, pyridine, pyrazine and pyrimidine, and the like. The term heteroaryl also includes polycyclic hetero-aromatic systems having two or more rings in which two atoms are common to two adjoining rings (the rings are “fused”) wherein at least one of the rings is a heteroaryl, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryl, heterocycles, and/or heteroaryls. Additionally, the heteroaryl group may be optionally substituted.

As used herein, “substituted” indicates that a substituent other than H is bonded to the relevant position, such as carbon. Thus, for example, where R1is mono-substituted, then one R1must be other than H. Similarly, where R1is di-substituted, then two of R1must be other than H. Similarly, where R1is unsubstituted, R1is hydrogen for all available positions.

The “silylated” or “germanylated” designation in the fragments described herein, i.e. silylated alkyl, germanylated alkyl, etc. means that one or more of the C atoms in the respective fragment can be replaced by a Si or Ge atom.

According to an aspect of the present disclosure, a composition comprising a first compound is disclosed. The first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature; wherein the first compound has at least one aromatic ring and at least one substituent R; wherein each of the at least one R is an organic group having at least one X—F bond; wherein each X is independently selected from the group consisting of Si, and Ge; and wherein each of the at least one R is directly bonded to one of the aromatic rings.

In some embodiments of the composition, each X is directly bonded to the aromatic ring. In some embodiments of the composition, each X is separated by at least one carbon atom from the aromatic ring. In some embodiments, X is separated by at least two carbon atoms from the aromatic ring. In some embodiments, each X is separated by at least three carbon atoms from the aromatic ring. In some embodiments, each X is Si. The composition of claim1, wherein each X is Ge. In some other embodiments, each X has only one F bonded to it. In other embodiments, each of the at least one R has only one atom of X. In other embodiments, each of the at least one R has at least two atoms of X.

In some embodiments of the composition, the first compound does not have any F atoms other than in the at least one R. In other embodiments, the first compound is capable of emitting light from a triplet excited state to a ground singlet state at room temperature.

In other embodiments, the first compound is a metal coordination complex having a metal-carbon bond. The metal can be selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Au, and Cu. In some embodiments, the metal is Ir. In some embodiments, the metal is Pt.

In some embodiments of the composition, each of the at least one R is independently selected from the group consisting of partially or fully fluorinated silylated alkyl, partially or fully fluorinated silylated cycloalkyl, partially or fully fluorinated germanylated alkyl, partially or fully fluorinated germanylated cycloalkyl, and combinations thereof.

In some embodiments of the composition, the first compound has the formula of M(L1)x(L2)y(L3)z; wherein L1, L2and L3can be the same or different;

wherein x is 1, 2, or 3;

wherein y is 0, 1, or 2;

wherein z is 0, 1, or 2;

wherein M is a metal and x+y+z is the oxidation state of the metal M;

wherein L1, L2and L3are each independently selected from the group consisting of:

wherein each X1to X13are independently selected from the group consisting of carbon and nitrogen;

wherein R′ and R″ are optionally fused or joined to form a ring;

wherein each Ra, Rb, Rc, and Rdmay represent from mono substitution to the possible maximum number of substitution, or no substitution;

wherein any two adjacent substitutents of Ra, Rb, Rc, and Rdare optionally fused or joined to form a ring or form a multidentate ligand; and

wherein at least one of the Ra, Rb, Rc, and Rdincludes at least one R. In the formula of M(L1)x(L2)y(L3)z, M can be selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Au, and Cu.

In some embodiments of the first compound having the formula of M(L1)x(L2)y(L3)z, the first compound has the formula of Ir(L1)2(L2) with L1and L2being defined as stated above.

In some embodiments of the first compound having the formula of Ir(L1)2(L2), L1has the formula selected from the group consisting of:

In some embodiments of the first compound having the formula of Ir(L1)2(L2), L2has the formula:

wherein Re, Rf, Rh, and Riare independently selected from group consisting of alkyl, cycloalkyl, aryl, and heteroaryl;

wherein at least one of Re, Rf, Rh, and Rihas at least two carbon atoms;

In some embodiments of the first compound having the formula of Ir(L1)2(L2), L1and L2are different and L1and L2are each independently selected from the group consisting of:

In some embodiments of the first compound having the formula of Ir(L1)2(L2), L1and L2are each independently selected from the group consisting of:

In some embodiments of the first compound having the formula of M(L1)x(L2)y(L3)z, the first compound has the formula of Pt(L1)2or Pt(L1)(L2). In some embodiments of the first compound having the formula of Pt(L1)2or Pt(L1)(L2), L1can be connected to the other L1or L2to form a tetradentate ligand.

In some embodiments of the first compound having the formula of M(L1)x(L2)y(L3)z, at least one of Ra, Rb, Rc, and Rdincludes an alkyl or cycloalkyl group that includes CD, CD2, or CD3, wherein D is deuterium.

In some embodiments of the composition of the present disclosure, each of the at least one R is selected from the group consisting of:

In some embodiments of the first compound having the formula of M(L1)x(L2)y(L3)z, at least one of L1, L2, and L3is selected from the group consisting of:

wherein Ry, and Rzare each independently selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, partially or fully deuterated variants thereof, and combinations thereof.

In some embodiments of the first compound having the formula of M(L1)x(L2)y(L3)z, the ligand L1is LAselected from the group consisting of:

In some embodiments of the first compound having the formula of M(L1)x(L2)y(L3)zand the ligand L1is one of LA1to LA342, the first compound is selected from the group consisting of Compound 1 through Compound 4,446; where each Compound x has the formula Ir(LAk)2(LBj); wherein x=342j+k−342, k is an integer from 1 to 342, and j is an integer from 1 to 13;

According to another aspect of the present disclosure, a first organic light emitting device is disclosed. The first organic light emitting device comprises: an anode;

a cathode; and

an organic layer, disposed between the anode and the cathode, comprising a first compound;

wherein the first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature;

wherein the first compound has at least one aromatic ring and at least one substituent R;

wherein each of the at least one R is an organic group having at least one X—F bond;

wherein each X is independently selected from the group consisting of Si, and Ge; and

wherein each of the at least one R is directly bonded to one of the aromatic rings.

In some embodiments, the first compound can be an emissive dopant. In some embodiments, the compound can produce emissions via phosphorescence, fluorescence, thermally activated delayed fluorescence, i.e., TADF (also referred to as E-type delayed fluorescence), triplet-triplet annihilation, or combinations of these processes.

The first organic light emitting device can be incorporated into a device selected from the group consisting of a consumer product, an electronic component module, and a lighting panel. The organic layer can be an emissive layer and the compound can be an emissive dopant in some embodiments, while the compound can be a non-emissive dopant in other embodiments.

The organic layer can also include a host. In some embodiments, the host can include a metal complex. The host can be a triphenylene containing benzo-fused thiophene or benzo-fused furan. Any substituent in the host can be an unfused substituent independently selected from the group consisting of CnH2n+1, OCnH2n+1, OAr1, N(CnH2n+1)2, N(Ar1)(Ar2), CH═CH—CnH2n+1, C≡C—CnH2n+1, Ar1, Ar1—Ar2, and CH2—Ar1, or no substitution. In the preceding substituents n can range from 1 to 10; and Ar1and Ar2can be independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and heteroaromatic analogs thereof.

The host can be a compound comprising at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiphene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene. The host can include a metal complex. The host can be a specific compound selected from the group consisting of:

and combinations thereof.

In yet another aspect of the present disclosure, a formulation comprising the first compound is disclosed, wherein the first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature; wherein the first compound has at least one aromatic ring and at least one substituent R; wherein each of the at least one R is an organic group having at least one X—F bond; wherein each X is independently selected from the group consisting of Si, and Ge; and

wherein each of the at least one R is directly bonded to one of the aromatic rings. The formulation can include one or more components selected from the group consisting of a solvent, a host, a hole injection material, hole transport material, and an electron transport layer material, disclosed herein.
Combination with Other Materials

Examples of aromatic amine derivatives used in HIL or HTL include, but are not limited to the following general structures:

In one aspect, the metal complexes are:

In another aspect, Met is selected from Ir and Pt. In a further aspect, (Y101-Y104) is a carbene ligand.

A hole blocking layer (HBL) may be used to reduce the number of holes and/or excitons that leave the emissive layer. The presence of such a blocking layer in a device may result in substantially higher efficiencies as compared to a similar device lacking a blocking layer. Also, a blocking layer may be used to confine emission to a desired region of an OLED.

wherein k is an integer from 1 to 20; L101is an another ligand, k′ is an integer from 1 to 3.
ETL:

In another aspect, the metal complexes used in ETL include, but are not limited to the following general formula:

In addition to and/or in combination with the materials disclosed herein, many hole injection materials, hole transporting materials, host materials, dopant materials, exciton/hole blocking layer materials, electron transporting and electron injecting materials may be used in an OLED. Non-limiting examples of the materials that may be used in an OLED in combination with materials disclosed herein are listed in Table A below. Table A lists non-limiting classes of materials, non-limiting examples of compounds for each class, and references that disclose the materials.

Compound 196 can be synthesized from the scheme below. The ligand for Compound 196, 2-(3,5-dimethylphenyl)-5-(fluorodimethylsilyl)quinoline, can be synthesized following the procedure reported in SYNLETT 2012, 23, 1064-1068. The iridium complex Compound 196 can be made following the procedure reported in US20080261076.