Chiral aggregation-induced emission luminogens with delayed fluorescence for circularly polarized organic light-emitting diodes
11871662 ยท 2024-01-09
Assignee
Inventors
Cpc classification
H10K85/6572
ELECTRICITY
C07D219/16
CHEMISTRY; METALLURGY
H10K85/626
ELECTRICITY
C07D209/86
CHEMISTRY; METALLURGY
International classification
C07D209/86
CHEMISTRY; METALLURGY
C07D219/16
CHEMISTRY; METALLURGY
C09K11/02
CHEMISTRY; METALLURGY
Abstract
Provided herein are chiral compounds that exhibit circularly polarized photoluminescence and electroluminescence and electroluminescent devices and circularly polarized fluorescent probes comprising the same.
Claims
1. A con pound of Formula I: ##STR00025## wherein X.sup.1 is selected from the group consisting of: ##STR00026## R.sup.1 for each instance is independently selected from the group consisting of halide, H, alkyl, alkene, alkyne, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, carboxyl, NR.sub.2, sulfonic acid, SR, and OR; Y is N(R), O, S, Se, Te, or C(R).sub.2; wherein at least one R.sup.1 optionally further comprises a terminal functional group selected from the group consisting of N.sub.3, NCS, SH, NH.sub.2, COOH, alkyne, N-hydroxysuccinimide ester, maleimide, hydrazide, nitrone group, CHO, OH, halide, and charged ionic group; and R for each instance is independently selected from the group consisting of H, alkyl, cycloalkylaryl, aryl, and heteroaryl, wherein the compound of Formula I is isolated, pure, or present in a film.
2. The compound of claim 1, wherein R.sup.1 for each instance is independently selected from the group consisting of H and alkyl.
3. The compound of claim 1, wherein R.sup.1 for each instance is independently selected from the group consisting of: ##STR00027## wherein Y is N(R), O, or C(R).sub.2 and R is independently H or alkyl.
4. The compound of claim 1, wherein X.sup.1 is ##STR00028## and R.sup.1 for each instance is H or alkyl.
5. The compound of claim 1, wherein the compound of Formula I is represented by: ##STR00029## wherein R.sup.1 is H or alkyl.
6. The compound of claim 1, wherein the compound of Formula I is represented by: ##STR00030## wherein R.sup.1 is H or alkyl.
7. The compound of claim 1, wherein the compound of Formula I is selected from the group consisting of: ##STR00031##
8. The compound of claim of claim 1, wherein the compound exhibits a photoluminescence dissymmetry factor in the solid state between 0.02 to 0.05 calculated from the maximum emission wavelength.
9. An electroluminescent device comprising the compound of claim 1.
10. The electroluminescent device of claim 9, wherein the electroluminescent device comprises: an anode; a hole-injection laver; a hole-transport layer; an electron-transport layer; an electron-injection layer; a light-emitting layer comprising the compound of Formula I; and a cathode layer, wherein at least one of the anode layer and the cathode layer being substantially transparent to electroluminescent light.
11. The electroluminescent device of claim 10, wherein the light-emitting layer further comprises a host matrix and the compound of Formula I is used as a dopant material.
12. The electroluminescent device of claim 9, wherein the compound of Formula I is: ##STR00032## wherein X.sup.1 is ##STR00033## and R.sup.1 for each instance is H or alkyl.
13. The electroluminescent device of claim 9, wherein the compound of Formula I is selected from the group consisting of: ##STR00034##
14. The electroluminescent device of claim 10, wherein the electron-injection layer comprises lithium-8-hydroxyquinolinolate (Liq), the electron-transport layer comprises 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB), the hole-injection layer comprises 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HATCN), the hole-transport layer comprises (TCTA), and the light-emitting layer further comprises N,N-dicarbazolyl-3,5-benzene (mCP).
15. The electroluminescent device of claim 14, wherein the compound of Formula I is selected from the group consisting of: ##STR00035##
16. The electroluminescent device of claim 10, wherein the compound exhibits an electroluminescence dissymmetry factor between 0.05 to 0.090 calculated from the maximum emission wavelength.
17. The electroluminescent device of claim 10, wherein the electroluminescent device has a maximum power efficiency between 18 to 20 lm.Math.W.sup.1.
18. The electroluminescent device of claim 10, wherein the electroluminescent device has a turn on voltage of 3.4 to 3.8 volts.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1) The above and other objects and features of the present disclosure will become apparent from the following description of the present invention, when taken in conjunction with the accompanying drawings, in which:
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DETAILED DESCRIPTION
Definitions
(34) The definitions of terms used herein are meant to incorporate the present state-of-the-art definitions recognized for each term in the chemical and semiconductor fields. Where appropriate, exemplification is provided. The definitions apply to the terms as they are used throughout this specification, unless otherwise limited in specific instances, either individually or as part of a larger group.
(35) The term heteroatom is art-recognized and refers to an atom of any element other than carbon or hydrogen. Illustrative heteroatoms include boron, nitrogen, oxygen, phosphorus, sulfur and selenium.
(36) The term alkyl is art-recognized, and includes saturated aliphatic groups, including straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl substituted cycloalkyl groups, and cycloalkyl substituted alkyl groups. In certain embodiments, a straight chain or branched chain alkyl has about 30 or fewer carbon atoms in its backbone (e.g., C.sub.1-C.sub.30 for straight chain, C.sub.3-C.sub.30 for branched chain), and alternatively, about 20 or fewer. Likewise, cycloalkyls have from about 3 to about 10 carbon atoms in their ring structure, and alternatively about 5, 6 or 7 carbons in the ring structure.
(37) Unless the number of carbons is otherwise specified, lower alkyl refers to an alkyl group, as defined above, but having from one to about ten carbons, alternatively from one to about six carbon atoms in its backbone structure. Likewise, lower alkenyl and lower alkynyl have similar chain lengths.
(38) The term aralkyl is art-recognized and refers to an alkyl group substituted with an aryl group (e.g., an aromatic or heteroaromatic group).
(39) The terms alkenyl and alkynyl are art-recognized and refer to unsaturated aliphatic groups analogous in length and possible substitution to the alkyls described above, but that contain at least one double or triple bond respectively.
(40) The term aryl is art-recognized and refers to 5-, 6- and 7-membered single-ring aromatic groups that may include from zero to four heteroatoms, for example, benzene, naphthalene, anthracene, pyrene, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, pyrazole, pyridine, pyrazine, pyridazine and pyrimidine, and the like. Those aryl groups having heteroatoms in the ring structure may also be referred to as aryl heterocycles or heteroaromatics. The aromatic ring may be substituted at one or more ring positions with such substituents as described above, for example, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, alkoxyl, amino, nitro, sulfhydryl, imino, amido, phosphonate, phosphinate, carbonyl, carboxyl, silyl, ether, alkylthio, sulfonyl, sulfonamido, ketone, aldehyde, ester, heterocyclyl, aromatic or heteroaromatic moieties, CF.sub.3, CN, or the like. The term aryl also includes polycyclic ring systems having two or more cyclic rings in which two or more carbons are common to two adjoining rings (the rings are fused rings) wherein at least one of the rings is aromatic, e.g., the other cyclic rings may be cycloalkyls, cycloalkenyls, cycloalkynyls, aryls and/or heterocyclyls.
(41) The terms ortho, meta and para are art-recognized and refer to 1,2-, 1,3- and 1,4-disubstituted benzenes, respectively. For example, the names 1,2-dimethylbenzene and ortho-dimethylbenzene are synonymous.
(42) The terms heterocyclyl, heteroaryl, or heterocyclic group are art-recognized and refer to 3- to about 10-membered ring structures, alternatively 3- to about 7-membered rings, whose ring structures include one to four heteroatoms. Heterocycles may also be polycycles. Heterocyclyl groups include, for example, thiophene, thianthrene, furan, pyran, isobenzofuran, chromene, xanthene, phenoxanthene, pyrrole, imidazole, pyrazole, isothiazole, isoxazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, indole, indazole, purine, quinolizine, isoquinoline, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, carbazole, carboline, phenanthridine, acridine, pyrimidine, phenanthroline, phenazine, phenarsazine, phenothiazine, furazan, phenoxazine, pyrrolidine, oxolane, thiolane, oxazole, piperidine, piperazine, morpholine, lactones, lactams such as azetidinones and pyrrolidinones, sultams, sultones, and the like. The heterocyclic ring may be substituted at one or more positions with such substituents as described above, as for example, halogen, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, amino, nitro, sulfhydryl, imino, amido, phosphonate, phosphinate, carbonyl, carboxyl, silyl, ether, alkylthio, sulfonyl, ketone, aldehyde, ester, a heterocyclyl, an aromatic or heteroaromatic moiety, CF.sub.3, CN, or the like.
(43) The term optionally substituted refers to a chemical group, such as alkyl, cycloalkyl aryl, and the like, wherein one or more hydrogen may be replaced with a with a substituent as described herein, for example, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, alkoxyl, amino, nitro, sulfhydryl, imino, amido, phosphonate, phosphinate, carbonyl, carboxyl, silyl, ether, alkylthio, sulfonyl, sulfonamido, ketone, aldehyde, ester, heterocyclyl, aromatic or heteroaromatic moieties, CF.sub.3, CN, or the like
(44) The terms polycyclyl or polycyclic group are art-recognized and refer to two or more rings (e.g., cycloalkyls, cycloalkenyls, cycloalkynyls, aryls and/or heterocyclyls) in which two or more carbons are common to two adjoining rings, e.g., the rings are fused rings. Rings that are joined through non-adjacent atoms are termed bridged rings. Each of the rings of the polycycle may be substituted with such substituents as described above, as for example, halogen, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, amino, nitro, sulfhydryl, imino, amido, phosphonate, phosphinate, carbonyl, carboxyl, silyl, ether, alkylthio, sulfonyl, ketone, aldehyde, ester, a heterocyclyl, an aromatic or heteroaromatic moiety, CF.sub.3, CN, or the like.
(45) The term carbocycle is art-recognized and refers to an aromatic or non-aromatic ring in which each atom of the ring is carbon.
(46) The term nitro is art-recognized and refers to NO.sub.2; the term halogen is art-recognized and refers to F, Cl, Br or I; the term sulfhydryl is art-recognized and refers to SH; the term hydroxyl means OH; and the term sulfonyl and sulfone is art-recognized and refers to SO.sub.2-. Halide designates the corresponding anion of the halogens.
(47) The representation as used herein in connection to chemical a group or moiety is intended to represent the covalent bond that the aforementioned chemical group or moiety is covalently bonded to another chemical group or moiety.
(48) The phrase aggregation-induced emission or AIE as used herein refers to the enhancement of light-emission by a fluorescent compound upon aggregation in the amorphous or crystalline (solid) states of the fluorescent compound, whereas the fluorescent compound exhibits weak or substantially no emission in dilute solutions.
(49) The term .sub.ex as used herein refers to the excitation wavelength.
(50) The term .sub.em as used herein refers to the emission wavelength.
(51) As used herein, isolated means that the compounds described herein are separated from other components of a synthetic organic chemical reaction mixture. The compounds described herein can be purified via conventional techniques. As used herein, purified means that when isolated, the isolate contains at least 95%, at least 98%, or more of a compound described herein by weight of the isolate.
(52) Enantiomers are a pair of stereoisomers that are non-superimposable mirror images of each other. A mixture of a pair of enantiomers in equal proportions can be known as a racemic mixture. The term (+/) is used to designate a racemic mixture where appropriate. The absolute stereochemistry can be specified according to the Cahn-Ingold-Prelog R-S system. When a compound is an enantiomer, the stereochemistry at each chiral carbon and/or axis of chirality can be specified by either R or S. Resolved compounds whose absolute configuration is unknown can be designated (+) or () depending on the direction (dextro- or levorotatory) which they rotate plane polarized light at the wavelength of the sodium D line. Certain compounds described herein can contain one or more asymmetric centers and/or axis of chirality and can thus give rise to enantiomers, diastereomers, and other stereoisomeric forms that can be defined, in terms of absolute stereochemistry at each asymmetric atom or axis of chirality, as (R)- or (S)-. The present compounds and methods are meant to include all such possible isomers, including substantially enantiopure forms and intermediate mixtures. Optically active (R)- and (S)-isomers can be prepared, for example, using chiral synthons or chiral reagents, or resolved using conventional techniques.
(53) The enantiomeric excess or % enantiomeric excess of a composition can be calculated using the equation shown below. In the example shown below, a composition contains 90% of one enantiomer, e.g., an S enantiomer, and 10% of the other enantiomer, e.g., an R enantiomer. ee=(9010)/100=80%.
(54) Thus, a composition containing 90% of one enantiomer and 10% of the other enantiomer is said to have an enantiomeric excess of 80%. Some compositions described herein contain an enantiomeric excess of at least about 1%, about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 75%, about 90%, about 95%, about 99%, or greater of the S enantiomer. In other words, the compositions contain an enantiomeric excess of the S enantiomer over the R enantiomer. In other embodiments, some compositions described herein contain an enantiomeric excess of at least about 1%, about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 75%, about 90%, about 95%, about 99%, or greater of the R enantiomer. In other words, the compositions contain an enantiomeric excess of the R enantiomer over the S enantiomer.
(55) For instance, an isomer/enantiomer can, in some embodiments, be provided substantially free of the corresponding enantiomer, and can also be referred to as optically enriched, enantiomerically enriched, enantiomerically pure, substantially enantiopure and non-racemic, as used interchangeably herein. These terms refer to compositions in which the amount of one enantiomer is greater than the amount of that one enantiomer in a control mixture of the racemic composition (e.g., greater than 1:1 by weight). For example, an enantiomerically enriched preparation of the S enantiomer, means a preparation of the compound having greater than about 50% by weight of the S enantiomer relative to the total weight of the preparation (e.g., total weight of S and R isomers), such as at least about 75% by weight, further such as at least about 80% by weight. In some embodiments, the enrichment can be much greater than about 80% by weight, providing a substantially enantiomerically enriched, substantially enantiomerically pure or a substantially non-racemic preparation, which refers to preparations of compositions which have at least about 85% by weight of one enantiomer relative to the total weight of the preparation, such as at least about 90% by weight, and further such as at least about 95% by weight. In certain embodiments, the compound provided herein is made up of at least about 90% by weight of one enantiomer. In other embodiments, the compound is made up of at least about 95%, about 98%, or about 99% by weight of one enantiomer.
(56) In some embodiments, the compound is a racemic mixture of (S)- and (R) isomers. In other embodiments, provided herein is a mixture of compounds wherein individual compounds of the mixture exist predominately in an (S)- or (R)-isomeric configuration. For example, in some embodiments, the compound mixture has an (S)-enantiomeric excess of greater than about 10%, greater than about 20%, greater than about 30%, greater than about 40%, greater than about 50%, greater than about 55%, greater than about 60%, greater than about 65%, greater than about 70%, greater than about 75%, greater than about 80%, greater than about 85%, greater than about 90%, greater than about 95%, greater than about 96%, greater than about 97%, greater than about 98%, or greater than about 99%. In some embodiments, the compound mixture has an (S)-enantiomeric excess of about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99%, or about 99.5%, or more. In some embodiments, the compound mixture has an (S)-enantiomeric excess of about 55% to about 99.5%, about 60% to about 99.5%, about 65% to about 99.5%, about 70% to about 99.5%, about 75% to about 99.5%, about 80% to about 99.5%, about 85% to about 99.5%, about 90% to about 99.5%, about 95% to about 99.5%, about 96% to about 99.5%, about 97% to about 99.5%, about 98% to about 99.5%, or about 99% to about 99.5%, or more than about 99.5%.
(57) In other embodiments, the compound mixture has an (R)-enantiomeric excess of greater than about 10%, greater than about 20%, greater than about 30%, greater than about 40%, greater than about 50%, greater than about 55%, greater than about 60%, greater than about 65%, greater than about 70%, greater than about 75%, greater than about 80%, greater than about 85%, greater than about 90%, greater than about 95%, greater than about 96%, greater than about 97%, greater than about 98%, or greater than about 99%. In some embodiments, the compound mixture has an (R)-enantiomeric excess of about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99%, or about 99.5%, or more. In some embodiments, the compound mixture has an (R)-enantiomeric excess of about 55% to about 99.5%, about 60% to about 99.5%, about 65% to about 99.5%, about 70% to about 99.5%, about 75% to about 99.5%, about 80% to about 99.5%, about 85% to about 99.5%, about 90% to about 99.5%, about 95% to about 99.5%, about 96% to about 99.5%, about 97% to about 99.5%, about 98% to about 99.5%, or about 99% to about 99.5%, or more than about 99.5%.
(58) The compounds described herein can exhibit a number of beneficial properties, such as CPEL, CPL, AIE, TICT and TADF, which makes them useful materials for the development of improved electroluminescent devices and fluorescent probes. In certain embodiments, the compound has the Formula I:
(59) ##STR00014##
(60) wherein each of X.sup.1 and X.sup.2 is independently selected from the group consisting of:
(61) ##STR00015##
(62) R.sup.1 for each instance is independently selected from the group consisting of halide, H, alkyl, alkene, alkyne, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, carboxyl, NR.sub.2, sulfonic acid, SR, and OR;
(63) Y is N(R), O, S, Se, Te, or C(R).sub.2;
(64) wherein at least one R.sup.1 optionally further comprises a terminal functional group selected from the group consisting of N.sub.3, NCS, SH, NH.sub.2, COOH, alkyne, N-hydroxysuccinimide ester, maleimide, hydrazide, nitrone group, CHO, OH, halide, and charged ionic group; and
(65) R for each instance is independently selected from the group consisting of H, alkyl, cycloalkyl, aryl, and heteroaryl, with the proviso that if X.sup.1 is N-carbazole, then X.sup.2 is not N-carbazole and if X.sup.1 is F, then X.sup.2 is not F.
(66) In certain embodiments, the compound of Formula I specifically excludes compounds of Formula I, wherein X.sup.1 is N-carbazole and X.sup.2 is N-carbazole; and/or X.sup.1 is F and X.sup.2 is F, as shown below.
(67) ##STR00016##
(68) In certain embodiments of the compound of Formula I, wherein X.sup.1 is N-carbazole and X.sup.2 is F, the compound is present in isolated and/or pure form and/or exists as a thin film.
(69) The compound of Formula I comprises a binaphthol moiety, which has an axis of chirality and consequently can exist as two non-superimposable mirror images. In certain embodiments, the compound of Formula I is substantially enantiopure and has an enantiomeric excess of the R enantiomer or the S enantiomer. In certain embodiments, the enantiomeric excess of the compound of Formula I is at least 30%, 40%, 50%, 60%, 70%, 80%, 85%, 90%, 93%, 95%, 97%, 98%, 99%, 99.5%, 99.9%, or greater.
(70) In certain embodiments, the compound of Formula I is present in the solid state, e.g., in a thin film. In certain embodiments, the compound of Formula I is present is the dopant in a host matrix.
(71) Y can be N(R), O, S, Se, Te, or C(R).sub.2, wherein R is H, alkyl, or cycloalkyl. In certain embodiments, Y is N(R), O, S, or C(R).sub.2, wherein R is H, C.sub.1-C.sub.10 alkyl, or C.sub.3-C.sub.7 cycloalkyl. In certain embodiments, Y is C(R).sub.2, wherein R is H, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.6 alkyl, C.sub.3-C.sub.6 cycloalkyl, or C.sub.5-C.sub.6 cycloalkyl. In certain embodiments, Y is C(R).sub.2, wherein R is H or C.sub.1-C.sub.6 alkyl.
(72) With reference to X.sup.1 and X.sup.2, the covalent bond between R.sup.1 and the aryl to which it is attached is intended to indicate that R.sup.1 can be covalently bonded to any position on the aryl ring, valency permitting. For example, R.sup.1 can be covalently bound to any of positions 1-8 of the following exemplary N-carbazole:
(73) ##STR00017##
(74) R.sup.1 for each instance can independently be fluoride, chloride, bromide, H, C.sub.1-C.sub.10 alkyl, C.sub.2-C.sub.10 alkene, C.sub.2-C.sub.10 alkyne, heteroalkyl, C.sub.3-C.sub.7 cycloalkyl, heterocycloalkyl, optionally substituted aryl, heteroaryl, carboxyl, NR.sub.2, sulfonic acid, SR, or OR. In certain embodiments, R.sup.1 for each instance is independently fluoride, H, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.6 alkyl, C.sub.3-C.sub.7 cycloalkyl, C.sub.5-C.sub.6 cycloalkyl, heterocycloalkyl, optionally substituted aryl, heteroaryl, carboxyl, NR.sub.2, sulfonic acid, SR, or OR. In certain embodiments, R.sup.1 for each instance is independently H, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.6 alkyl, C.sub.3-C.sub.6 cycloalkyl, or C.sub.5-C.sub.6 cycloalkyl. In certain embodiments, R.sup.1 for each instance is independently F, Cl, H, or C.sub.1-C.sub.6 alkyl.
(75) R.sup.1 can optionally further comprise reactive functionality capable forming a covalent bond with complimentary functionality present in an active agent thereby forming an active agent CPL conjugate. The active agent can be a small molecule, polypeptide, protein, antibody, or antibody fragment that is capable of selectively binding to a specific peptide, protein, carbohydrate, lipid, feature(s) found on cell membrane, organelle, organ, tissues and/or other antigen and can allow the active agent CPL conjugate selectively bind, detect, analyze, and/or image analytes, antigens, cells, organs, tissues, or other species of interest. In such instances, R.sup.1 can further comprise a terminal functional group selected from the group consisting of N.sub.3, NCS, SH, NH.sub.2, COOH, alkyne, N-hydroxysuccinimide ester, maleimide, hydrazide, nitrone group, CHO, OH, halide, and charged ionic group. In certain embodiments, R.sup.1 is (CH.sub.2).sub.nQ, wherein n is an integer between 0-8 and Q is the terminal functional group. In certain embodiments, Q is N.sub.3, NH.sub.2, COOH, alkyne, N-hydroxysuccinimide ester, or maleimide. The selection of the appropriate terminal functional group, the complimentary reactive functionality present in an active agent and conditions for their reaction are well within the skill of a person of ordinary skill in the art.
(76) In certain embodiments, R for each instance is independently selected from the group consisting of H, C.sub.1-C.sub.10 alkyl, and C.sub.3-C.sub.7 cycloalkyl. In certain embodiments, R for each instance is independently selected from the group consisting of H, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.6 alkyl, C.sub.3-C.sub.7 cycloalkyl, C.sub.3-C.sub.6 cycloalkyl, C.sub.4-C.sub.6 cycloalkyl, and C.sub.5-C.sub.6 cycloalkyl.
(77) In certain embodiments, each of X.sup.1 and X.sup.2 is independently selected from the group consisting of:
(78) ##STR00018##
(79) wherein R.sup.1 for each instance is independently H, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.6 alkyl, C.sub.3-C.sub.6 cycloalkyl, or C.sub.5-C.sub.6 cycloalkyl.
(80) In certain embodiments, each of X.sup.1 and X.sup.2 is independently selected from the group consisting of:
(81) ##STR00019##
(82) R.sup.1 for each instance is independently H, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.6 alkyl, C.sub.3-C.sub.6 cycloalkyl, or C.sub.5-C.sub.6 cycloalkyl.
(83) In certain embodiments, each of X.sup.1 and X.sup.2 is independently selected from the group consisting of:
(84) ##STR00020##
(85) wherein Y is N(R), O, or C(R).sub.2; R is independently H or alkyl; and R.sup.1 for each instance is independently H, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.6 alkyl, C.sub.3-C.sub.6 cycloalkyl, or C.sub.5-C.sub.6 cycloalkyl.
(86) In certain embodiments, each of X.sup.1 and X.sup.2 is independently selected from the group consisting of:
(87) ##STR00021##
(88) wherein Y is N(R), O, or C(R).sub.2 and R is independently H or C.sup.1-C.sup.6 alkyl.
(89) In certain embodiments, the compound of Formula I is represented by:
(90) ##STR00022##
(91) wherein R.sup.1 is H or alkyl and R.sup.2 is alkyl; or R.sup.1 is C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.6 alkyl, and R.sup.2 is C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.6 alkyl; or R.sup.1 is H and R.sup.2 is C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.6 alkyl, and R.sup.2 is C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.6 alkyl.
(92) In certain embodiments, the compound of Formula I is represented by:
(93) ##STR00023##
(94) wherein R.sup.1 is H or alkyl with the proviso that if R.sup.1 is H, the compound is isolated, pure, or present in a film; or R.sup.1 is C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.6 alkyl.
(95) In certain embodiments, the compound of Formula I is represented by:
(96) ##STR00024##
(97) wherein R.sup.1 is H or alkyl; or R.sup.1 is C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.6 alkyl.
(98) The EL properties of the compound of Formula I can be particularly useful in the fabrication of luminescent devices, such as variously configured CPOLED. CPOLEDs that can be fabricated using the compounds of Formula I include from very simple structures having a single anode and cathode (e.g., monolayer CPOLEDs) to more complex devices, such as 2-layer or multilayer heterostructure configurations.
(99) In certain embodiments, the CPOLED comprises an anode, a cathode, and a light emissive layer disposed between the anode and the cathode. In certain embodiments the CPOLED further comprises a hole-transport layer.
(100) In certain embodiments, the CPOLED has the structure shown in
(101) In certain embodiments, the electron-injection layer 160 can be subdivided into two or more sublayers (not shown). In one illustrative example of the CPOLED, the electron-injection layer 170 is further divided into two sublayers, a first electron-injection layer adjacent to the electron-transport layer 150 and a second electron-injection layer located between the first electron-injection layer and the cathode.
(102) In certain embodiments, the hole-injection layer 120 can be subdivided into two or more sublayers (not shown). In one illustrative example of the CPOLED device, the hole-injection layer 120 is further divided into two sublayers, a first hole-injection layer adjacent to the hole-transport layer 130 and a second hole-injection layer located between the first hole-injection layer and the anode.
(103) In certain embodiments, there is a hole-blocking layer between the light-emitting layer 140 and the electron-transport layer 150 (not shown).
(104) The CPOLED can be configured such that the EL emission of the anode or alternatively through the cathode. When the EL emission occurs through the anode, the anode 110 should be transparent or substantially transparent to the emitted wavelengths. Commonly used transparent anode materials include, but are not limited to, indium-tin oxide (ITO), indium-zinc oxide (IZO) tin oxide, aluminum- or indium-doped zinc oxide, magnesium-indium oxide, nickel-tungsten oxide, gallium nitride, zinc selenide, zinc sulfide. When the EL emission occurs through the cathode 170, the optical properties of the anode 110 are immaterial and any conductive material, transparent, opaque or reflective can be used. Example conductors for this application include, but are not limited to, gold, iridium, molybdenum, palladium, and platinum.
(105) The anode 110 can be deposited using any suitable way such as evaporation, sputtering, chemical vapor deposition, or electrochemical processes. Anodes can be patterned using, e.g., conventional photolithographic processes.
(106) The hole-injection material can serve to facilitate injection of holes into the hole-transport layer 130. The hole-injection layer 120 can be formed of any hole-injection material including those that are commonly used. Non-limiting examples of hole-injection materials are N,N-diphenyl-N,N-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4-diamine (DNTPD), a phthalocyanine compound such as copper phthalocyanine, 4,4,4-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), N,N-di(1-naphthyl-N,N-diphenylbenzidine) (NPB), 4,4,4-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4,4-tris-(N-(naphthylen-2-yl)-N-phenylamino)triphenylamine (2-TNATA), polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (Pani/CSA), (polyaniline)/poly(4-styrenesulfonate) (PANI/PSS), tetracyanoquinonedimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ) and additional hole-injection materials, such as dipyrazino[2,3-f:2,3-h]quinoxalinehexacarbonitrile (HATCN) are described in U.S. Publication 2004/0113547 A1 and U.S. Pat. No. 6,720,573.
(107) The hole-injection material can be deposited using any suitable conventional method known in the art including, but not limited to, vacuum deposition, spin coating, printing, print screening, spraying, painting, doctor-blading, slot-die coating, and dip coating.
(108) The hole-transport layer 130 can be formed of any hole-transport material including those that are commonly used. Non-limiting examples of suitable known hole-transport materials are carbazole derivatives, such as N-phenylcarbazole or polyvinylcarbazole, N,N-bis(3-methylphenyl-N,N-diphenyl-[1,1-biphenyl]-4,4-diamine (TPD), 4,4,4-tris(N-carbazolyl)triphenylamine (TCTA), (4,4-(cyclohexane-1,1-diyl)bis(N,N-di-p-tolylaniline)) (TAPC), and N,N-di(1-naphthyl-N,N-diphenylbenzidine) (NPB).
(109) The hole-transport material can be deposited using any suitable conventional method known in the art including, but not limited to, vacuum deposition, spin coating, printing, print screening, spraying, painting, doctor-blading, slot-die coating, and dip coating.
(110) The light-emitting layer 140 can comprise a substantially pure thin film comprising a compound of Formula 1 or a host matrix doped with a compound of Formula I. In instance in which the light-emitting layer comprises a host matrix, the host matrix can be any host matrix material known in the art. Non-limiting examples of host matrix materials include bis(4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl)methanone, 9-(4-(4,6-diphenylpyrimidin-2-yl)phenyl)-9H-carbazole, 4-(4-diphenylaminophenyl)diphenylsulfone, 9-(9-phenyl-9H-carbazol-3-yl)-9-p-tolyl-9H-fluorene-3-carbonitrile, 3,5-di(9H-carbazol-9-yl)benzonitrile, 2-(diphenylphosphinyl)-spiro[9H-fluorene-9,9-quino[3,2,1-kl]phenoxazine], 2,8-bis(diphenylphosphoryl)dibenzo[b,d]thiophene, 4,4-bis(carbazol-9-yl)biphenyl, 4,4,4-tris(carbazol-9-yl)triphenylamine, 2,6-bis(9,9-diphenylacridin-10(9H)-yl)pyrazine, 1,3-bis(carbazol-9-yl)benzene, 4,4,4-Tris(carbazol-9-yl)triphenylamine, 4,4-bis(carbazol-9-yl)biphenyl, 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole, 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, 2,8-bis(diphenylphosphoryl)dibenzo[b,d]thiophene, bis[2-(diphenylphosphino)phenyl]ether oxide, 2,6-di(9H-carbazol-9-yl)pyridine, 3,5-di(carbazol-9-yl)-[1,1-biphenyl]-3,5-dicarbonitrile, 4,4-(9H,9H-3,3-bicarbazole-9,9-diyl)bis(N,N-diphenylaniline), 4-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile, 3-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile, 2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan, and 3,5-di(carbazol-9-yl)-1-phenylsulfonylbenzene. The compound of Formula 1 can be present in the host material at a concentration of 1-20% w/w.
(111) The light-emitting material can be deposited using any suitable conventional method known in the art including, but not limited to, vacuum deposition, spin coating, printing, print screening, spraying, painting, doctor-blading, slot-die coating, and dip coating.
(112) Any suitable electron-transport material may be used to form the electron-transport layer 150. As the electron-transport material, any electron-transporting material that can stably transport electrons injected from an electron injecting electrode (cathode) may be used as a material for the electron-transport layer. Non-limiting examples of useful electron-transport materials may include quinoline derivatives such as tris(8-quinolinorate)aluminum (Alq3), 3-(biphenyl-4-yl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ), bis(2-methyl-8-quinolinato-N1,O8)-(1,1-biphenyl-4-olato)aluminum (BAlq), beryllium bis(benzoquinolin-10-olate) (Bebq2), 9,10-di(naphthalene-2-yl)anthracene (ADN), and (3,3,5,5-tetra(pyridin-3-yl)-1,1:3,1-terphenyl (BmPyPhB).
(113) The electron-transport material can be deposited using any suitable conventional method known in the art including, but not limited to, vacuum deposition, spin coating, printing, print screening, spraying, painting, doctor-blading, slot-die coating, and dip coating.
(114) Any suitable electron-injection material may be used to form the electron-injection layer 160. Non-limiting examples of electron injecting materials useful for forming the electron-injection layer 160 are LiF, NaCl, CsF, Li.sub.2O, 8-hydroxyquinolinolato-lithium (Liq) and BaO.
(115) The electron-injection material can be deposited using any suitable conventional method known in the art including, but not limited to, vacuum deposition, spin coating, printing, print screening, spraying, painting, doctor-blading, slot-die coating, and dip coating.
(116) The cathode 170 can comprise any anodic material known to those of skill in the art. In certain embodiments, the anode comprises lithium, magnesium, calcium, aluminum, gold, indium, copper, silver, or a combination thereof. In certain embodiments, the anode comprises aluminum.
(117) The cathode 170 can be deposited using any suitable way such as evaporation, sputtering, chemical vapor deposition, or electrochemical processes. Anodes can be patterned using, e.g., conventional photolithographic processes.
(118) The luminescent devices described herein can be incorporated into a wide variety of consumer products, including flat panel displays, computer monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads up displays, fully transparent displays, flexible displays, cell phones, personal laptop computers, digital cameras, camcorders, viewfinders, micro-displays, vehicles, a large area wall, theater or stadium screen, or a sign.
(119) The materials and structures described herein may have applications in devices other than CPOLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors may employ the materials and structures. More generally, organic devices, such as organic transistors, may employ the materials and structures described herein.
(120)
(121) The single-crystal structures of R-BN-CF, S-BN-DCB and S-BN-AF from crystallography analysis are displayed in
(122) To gain a better insight into the electron cloud distribution and geometrical structures of R/S-BN-CF, R/S-BN-CCB, R/S-BN-DCB and R/S-BN-AF, the molecular simulations were calculated by DFT B3LYP/6-31G* method with the Gaussian 09 package. The lowest unoccupied molecular orbitals (LUMOs) are mainly located on the central phenyl with cyano substitution, whereas the highest occupied molecular orbitals (HOMOs) occupy the electron-donating Cz and DMAC moieties (
(123) Photophysical Properties.
(124) The UV-Vis absorption and photoluminescence (PL) spectra for S-BN-CF, S-BN-CCB, S-BN-DCB and S-BN-AF solutions in toluene are illustrated in
(125) For a comprehensive investigation, the AIE and TICT properties of S-BN-CF, S-BN-CCB, S-BN-DCB and S-BN-AF were investigated in THF/H.sub.2O mixtures for different f.sub.w values. Taking the fluorescence spectra of S-BN-CF as an example (
(126) S-BN-CF, S-BN-CCB, S-BN-DCB and S-BN-AF show PL maximum in neat film at 520, 538, 553 and 580 nm, respectively (
(127) Chiroptical
(128) The CD spectra of R/S-BN-CF, R/S-BN-CCB, R/S-BN-DCB and R/S-BN-AF in toluene solution and neat film were also investigated. As is evident from
(129) CPL is the emission analog of CD that reflects the chiroptical properties of the luminescent molecules upon excitation.
(130) CPOLEDs Performance
(131) Inspired by the efficient RISC, delayed fluorescence characteristics, high glum value in film (10.sup.2) and excellent chiroptical properties, the development of the exemplary compounds' promising application as the emitters in circularly polarized electroluminescent devices was investigated. Initially, S-BN-CF was chosen to optimize the device structure due to its high k.sub.RISC (3.86710.sup.6 s.sup.1) in doped film among the exemplary compounds. The performance of an electroluminescent device comprising a film doped with S-BN-CF were evaluated by fabricating OLEDs with the following device configuration: (ITO)/HATCN (10 nm)/TAPC:HATCN (5:2, 60 nm)/TCTA (20 nm)/mCP: 10% S-BN-CF (20 nm)/BmPyPB (10 nm)/BmPyPB: 8% Liq (40 nm)/Liq (1.5 nm)/(Al). In the exemplary CPOLED device HATCN (dipyrazino[2,3-f:2,3-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile) and 8-hydroxyquinolinolato-lithium (Liq) serve as the hole-injection layer and the electron-injection layer, respectively, TCTA (tris(4-(9H-carbazol-9-yl)phenyl)amine) and TAPC (4,4-(cyclohexane-1,1-diyl) bis(N,N-di-p-tolylaniline)) serve as the hole-transport layer (HTL), BmPyPhB (3,3,5,5-tetra(pyridin-3-yl)-1,1:3,1-terphenyl) serves as the electro-transport layer (ETL), and 1,3-di(9H-carbazol-9-yl)benzene (mCP) acts as a host matrix. The details of device structures are illustrated in
(132) In a set of comparable experiments, nondoped OLEDs were fabricated (Device E-H) with the following device configuration: (ITO)/HATCN (10 nm)/TAPC (60 nm)/mCP (10 nm)/Enantiomers (20 nm)/BmPyPB (50 nm)/Liq (2.5 nm)/Al for CPOLEDs characteristics. The BN-CF, BN-CCB, BN-DCB and BN-AF nondoped based devices can emit EL emission with the peaks centered at 537, 563, 550 and 597 nm, respectively. The maximum luminance (L.sub.max), current (.sub.c), and external quantum (.sub.ext) efficiencies are 2570 cd m.sup.2, 10.28 cd A.sup.1 and 3.51% for BN-CF, 6633 cd m.sup.2, 6.33 cd A.sup.1 and 2.31% for BN-CCB, 5729 cd m.sup.2, 8.73 cd A.sup.1 and 2.93% for BN-DCB, 1473 cd m.sup.2, 1.09 cd A.sup.1 and 1.56% for BN-AF, respectively. In certain embodiments, the maximum luminance of a electroluminescent device comprising a nondoped film of the compound of Formula I is (L.sub.max) is 1,473 to 6,633, 2,570 to 6,633, 2,948 to 6,633, 3,032 to 6,633, 4,199 to 6,633, or 5,056 to 6,633 cd m.sup.2. In certain embodiments, the external quantum (.sub.ext) efficiency of the electroluminescent device comprising a nondoped film of the compound of Formula I is 0.6 to 9.3, 1.7 to 9.3, 2.3 to 9.3, 2.9 to 9.3, 3.5 to 9.3, or 6.3 to 9.3%. Importantly, the nondoped OLEDs can retain high EL efficiencies as luminescence increases. For example, at 1000 cd m.sup.2, the .sub.c, .sub.p and .sub.ext are 9.1 cd A.sup.1, 3.2 lm W.sup.1 and 3.1%, respectively, which are almost the same as the maximum values. The roll-off of current efficiency for nondoped OLED is 11.7% which is much smaller than the roll-off value of 53.3% for doped OLED [Table 2 (
(133) To compare the g-factors of the both enantiomers of BN-CF, we investigated the CPEL characteristic of the enantiomers' devices. The obtained left or right-circularly polarized electroluminescence spectra were taken under the voltage of 6 V. The two different enantiomers resulted in circularly polarized emission with opposite g.sub.EL signs, indicating that the chiral BINOL skeleton is responsible for the observed CP effect. At the emission maximum of 496 nm, the g.sub.EL of enantiomers doped based devices were +0.026 for S-BN-CF and 0.021 for R-BN-CF, respectively (
(134) In view of electroluminescent devices described herein, there are only 11 papers published since 1997 to now, and the relevant key data of the devices are listed in Table 5 (
Examples
(135) All solvents and reagents were commercially available and analytical-reagent-grade. DMF was purified by distillation over calcium hydride in the presence of benzophenone.
(136) .sup.1H and .sup.13C NMR spectra were measured on a Bruker ARX 400 NMR spectrometer and reported as parts per million (ppm) from the internal standard TMS. High-resolution mass spectra (HR-MS) were obtained on a Finnigan MAT TSQ 7000 Mass Spectrometer System operated in a MALDI-TOF mode. Single crystal data was collected on a Bruker Smart APEXII CCD diffractometer using graphite monochromated Cu K radiation (=1.54178 ). The photos and videos were recorded by a Cannon EOS 60D. Thermogravimetric analysis (TGA) was performed on a TA TGA Q5000 under nitrogen at a heating rate of 10 C. min.sup.1. Differential scanning calorimetry (DSC) analysis was performed on a TA Instruments DSC Q1000 at a heating rate of 10 C. min.sup.1. Electrochemical measurements were performed on a CHI610D electrochemical workstation in a three-electrode cell using a platinum button as working electrode, a platinum wire as counter electrode and a saturated calomel electrode as reference electrode in CH.sub.3CN solution with 0.1 M Bu.sub.4N.sup.+PF.sub.6.sup. at a scan rate of 100 mV/s and ferrocene as internal standard.
(137) Absorption spectra were measured on a Milton Roy Spectronic 3000 Array spectrophotometer. Steady-state photoluminescence (PL) spectra were measured on a Perkin-Elmer spectrofluorometer LS 55. The lifetime and temperature dependent photoluminescence spectra and absolute luminescence quantum yield were measured on a Edinburgh FLSP 920 fluorescence spectrophotometer equipped with a xenon arc lamp (Xe900), a microsecond flash-lamp (uF900), a picosecond pulsed diode laser (EPL-375), a closed cycle cryostate (CS202*I-DMX-1SS, Advanced Research Systems) and an integrating sphere (0.1 nm step size, 0.3 second integration time, 5 repeats), respectively. Mean decay times (.sub.P) were obtained from individual lifetimes .sub.i and amplitudes a.sub.i of multi-exponential evaluation. Circular dichroism (CD) spectra were recorded with a Chirascan spectrometer (Applied Photophysics, England). Circularly polarized photoluminescence (CPPL) spectra of the films and solution were recorded at 50 nm min.sup.1 scan speed with a commercialized instrument JASCO CPL-300 at room temperature with the resolution of 15 nm. Circularly polarized photoluminescence (CPEL) spectra were recorded on an instrument according to literature procedures..sup.1 Left-handed and right-handed CP emission spectra from the thin films were collected using a linear polarizer and quarter-wave plate prior to an Ocean Optics Fiber Flame-S-VIS-NIR spectrophotometer.
(138) The crystalline samples of R-BN-CF and S-BN-DCB were obtained from slowly evaporative crystallization using hexane/acetate mixture (10:1, v/v). The crystalline sample of S-BN-AF were obtained from slowly evaporative crystallization using CH.sub.2Cl.sub.2/C.sub.2H.sub.5OH mixture (1:5, v/v).
(139) Preparation of R/S-BN-CF
(140) A mixture of R/S-1 (1.0 g, 2.24 mmol), carbazole (374 mg, 2.24 mmol) and K.sub.2CO.sub.3 (464 mg, 3.36 mmol) was dissolved in anhydrous DMF (30 mL). The mixture was stirred for 3 h at room temperature. And then water (60 mL) was added. The mixture was extracted with ethyl acetate (330 mL). The combined organic layers were dried with anhydrous Na.sub.2SO.sub.4 and evaporated under reduced pressure to obtain the crude product. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=10:1) to yield 980 mg (74%) of the product as a yellow powder after removal of the solvent. .sup.1H NMR (400 Hz, CDCl.sub.3): 8.20-8.04 (m, 4H), 8.06 (dd, J.sub.1=8.0 Hz, J.sub.2=5.2 Hz, 2H), 7.71-7.60 (m, 4H), 7.57-7.37 (m, 8H), 7.20 (d, J=8.0 Hz, 1H), 7.13 (d, J=7.6 Hz, 1H). .sup.13C NMR (100 Hz, CDCl.sub.3): 156.9, 154.2, 150.95, 150.92, 149.3, 149.0, 148.56, 148.53, 139.86, 139.82, 132.5, 132.4, 132.04, 132.00, 131.89, 131.83, 128.6, 127.7, 126.75, 126.73, 126.69, 126.65, 124.94, 124.90, 124.41, 124.35, 124.31, 121.8, 120.91, 120.87, 120.35, 120.26, 113.45, 113.42, 111.08, 111.05, 109.56, 109.54, 109.3, 103.2, 103.1. HRMS (MALDI-TOF, m/z): [M].sup.+ calcd for C.sub.40H.sub.20FN.sub.3O.sub.2, 593.1540. found, 593.1524.
(141) Preparation of R/S-BN-CCB
(142) A mixture of R/S-BN-CF (1.33 g, 2.24 mmol), 3,6-di-tert-butyl-carbazole (749 mg, 2.68 mmol) and K.sub.2CO.sub.3 (464 mg, 3.36 mmol) was dissolved in anhydrous DMF (40 mL). The mixture was stirred for 3 h at room temperature. And then water (60 mL) was added. The mixture was extracted with ethyl acetate (330 mL). The combined organic layers were dried with anhydrous Na.sub.2SO.sub.4 and evaporated under reduced pressure to obtain the crude product. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=15:1) to yield 1.71 g (2.01 mmol, 91%) of the product as a pale yellow powder after removal of the solvent. .sup.1H NMR (400 Hz, CDCl.sub.3): 8.20 (dd, J.sub.1=8.8 Hz, J.sub.2=3.2 Hz, 2H), 8.09 (d, J=8.4 Hz, 2H), 7.81 (td, J.sub.1=10.4 Hz, J.sub.2=4.0 Hz, 2H), 7.68-7.56 (m, 8H), 7.51 (t, J=7.6 Hz, 2H), 7.22-7.08 (m, 4H), 7.04-6.93 (m, 2H), 6.74-6.67 (m, 2H), 6.59-6.53 (m, 2H). 1.40 (s, 9H), 1.30 (s, 9H). .sup.13C NMR (100 Hz, CDCl.sub.3): 150.9, 150.6, 149.4, 144.4, 144.1, 139.0, 138.5, 137.5, 136.9, 136.1, 134.9, 132.5, 132.1, 131.8, 128.6, 127.7, 126.8, 126.6, 125.7, 125.0, 124.8, 124.5, 124.3, 124.2, 124.0, 123.2, 122.5, 121.2, 120.9, 120.74, 120.71, 120.06, 119.56, 116.3, 115.7, 114.56, 114.47, 112.06, 111.93, 109.87, 109.81, 109.51, 109.31, 34.66, 34.47, 31.89, 31.74. HRMS (MALDI-TOF, m/z): [M].sup.+ calcd for C.sub.60H.sub.44N.sub.4O.sub.2, 852.3464. found, 852.3493.
(143) Preparation of R/S-BN-DCB
(144) To a mixture of R/S-1 (1.0 g, 2.24 mmol), 3,6-di-tert-butyl-carbazole (1.56 g, 5.60 mmol) and K.sub.2CO.sub.3 (1.54 g, 11.20 mmol), 40 mL anhydrous DMF was added. The reaction mixture was stirred at room temperature for 5 h. After completed the reaction, water (80 mL) was added. The mixture was extracted with ethyl acetate (340 mL). The combined organic layers were dried with anhydrous Na.sub.2SO.sub.4 and evaporated under reduced pressure to obtain the crude product. The residue was purified by silica-gel column chromatography using hexane/ethyl acetate (15:1) as an eluent. R/S-BN-DCB was obtained as a yellow solid in 81% yield (1.75 g, 1.81 mmol). .sup.1H NMR (400 Hz, CDCl.sub.3): 8.21 (d, J=8.8 Hz, 2H), 8.10 (d, J=8.0 Hz, 2H), 7.83 (d, J=8.8 Hz, 2H), 7.66-7.60 (m, 6H), 7.53-7.47 (m, 4H), 7.17 (d, J=8.8 Hz, 2H), 6.95 (d, J=8.4 Hz, 2H), 6.60 (d, J=8.8 Hz, 2H), 6.34 (d, J=8.4 Hz, 2H), 1.42 (s, 18H), 1.31 (s, 18H). .sup.13C NMR (100 Hz, CDCl.sub.3): 150.2, 149.5, 144.2, 143.8, 137.2, 136.6, 135.0, 132.5, 132.1, 131.8, 128.6, 127.6, 126.8, 126.6, 125.1, 124.7, 124.2, 123.3, 122.4, 120.8, 116.0, 115.3, 114.2, 112.3, 109.3, 109.2, 34.6, 34.4, 31.9, 31.8. HRMS (MALDI-TOF, m/z): [M].sup.+ calcd for C.sub.68H.sub.60N.sub.4O.sub.2, 964.4716. found, 964.4685.
(145) Preparation of R/S-BN-AF
(146) In a three-necked flask, 9,9-dimethyl-9,10-dihydroacridine (468 mg, 2.24 mmol) and t-BuOK (300 mg, 2.68 mmol) were dissolved in anhydrous CH.sub.3CN (30 mL) and followed by stirring at 90 C. for an hour. And then R/S-1 (1.0 g, 2.24 mmol) was added in the reaction and stirred at 90 C. for another 1.5 h. After cooling to room temperature, the solvent was removed by a rotary evaporator. And then water (60 mL) was added. The mixture was extracted with ethyl acetate (320 mL). The combined organic layers were dried with anhydrous Na.sub.2SO.sub.4 and evaporated under reduced pressure to obtain the crude product. The residue was purified by silica-gel column chromatography using hexane/ethyl acetate (15:1) as an eluent. R/S-BN-AF was obtained as an orange solid in 45% yield (630 mg, 1.0 mmol). .sup.1H NMR (400 Hz, CDCl.sub.3): 8.15 (d, J=8.8 Hz, 1H), 8.10 (d, J=9.2 Hz, 1H), 8.02 (t, J=7.6 Hz, 2H), 7.68 (d, J=8.8 Hz, 1H), 7.60-7.43 (m, 9H), 7.10 (t, J=6.0 Hz, 2H), 7.05 (t, J=4.4 Hz, 2H), 1.83 (s, 3H), 1.63 (s, 3H). .sup.13C NMR (100 Hz, CDCl.sub.3): 158.7, 156.1, 151.0, 148.7, 148.60, 148.56, 148.4, 137.6, 131.8, 131.7, 131.41, 131.35, 131.2, 130.7, 130.6, 128.0, 127.05, 126.8, 126.6, 126.5, 126.4, 126.11, 126.08, 126.06, 125.99, 125.44, 125.37, 124.29, 124.25, 122.1, 119.8, 119.6, 116.3, 116.2, 112.1, 111.8, 110.8, 110.7, 108.7, 103.0, 102.8, 35.5, 32.5, 28.4. HRMS (MALDI-TOF, m/z): [M].sup.+ calcd for C.sub.43H.sub.26FN.sub.3O.sub.2, 635.2009. found, 635.2019.
(147) Fabrication of CPOLED
(148) The Exemplary CPOLEDs were fabricated by sequential vacuum evaporation. The device configuration was as follows: indium tin oxide (ITO)/HATCN (10 nm)/TAPC:HATCN (5:2, 60 nm)/TCTA (20 nm)/mCP:10% target compounds (20 nm)/BmPyPB (10 nm)/BmPyPB:8% Liq (40 nm)/Liq (1.5 nm)/(Al). HATCN (dipyrazino[2,3-f:2,3-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile) and 8-hydroxyquinolinolato-lithium (Liq) serve as the hole-injection layer and the electron-injection layer, respectively. TCTA (tris(4-(9H-carbazol-9-yl)phenyl)amine) and TAPC (4,4-(cyclohexane-1,1-diyl)bis(N,N-di-p-tolylaniline)) serve as the hole-transport layer and, BmPyPhB (3,3,5,5-tetra(pyridin-3-yl)-1,1:3,1-terphenyl) serves as the electron-transport layer. mCP acts as a host to confine the triplet excitons within the guest emitters. The details of device structures are illustrated in