Patent Application
20190202975
The present invention relates to a process for preparing an organic charge transporting film.
There is a need for an efficient process for manufacturing an organic charge transporting film for use in a flat panel organic light emitting diode (OLED) display. Solution processing is one of the leading technologies for fabricating large flat panel OLED displays by deposition of OLED solution onto a substrate to form a thin film followed by cross-linking and polymerization. Currently, solution processable polymeric materials are cross-linkable organic charge transporting compounds. For example, U.S. Pat. No. 7,037,994 discloses an antireflection film-forming formulation comprising at least one polymer containing an acetoxymethylacenaphthylene or hydroxyl methyl acenaphthylene repeating unit and a thermal or photo acid generator (TAG, PAG) in a solvent. However, this reference does not disclose the formulation described herein.
The present invention provides a single liquid phase formulation useful for producing an organic charge transporting film; said formulation comprising: (a) a polymer resin having Mw at least 3,000 and comprising arylmethoxy linkages; (b) an acid catalyst which is an organic Bronsted acid with pKa≤4; a Lewis acid comprising a positive aromatic ion and an anion which is (i) a tetraaryl borate having the formula
wherein R represents zero to five non-hydrogen substituents selected from D, F and CF3, (ii) BF4−, (iii) PF6−, (iv) SbF6−, (v) AsF6− or (vi) ClO4−; or a thermal acid generator (TAG) which is an ammonium or pyridinium salt of an organic Bronsted acid with pKa≤2 or an ester of an organic sulfonic acid; and (c) a solvent.
Percentages are weight percentages (wt %) and temperatures are in ° C., unless specified otherwise. Operations were performed at room temperature (20-25° C.), unless specified otherwise. Boiling points are measured at atmospheric pressure (ca. 101 kPa). Molecular weights are in Daltons and molecular weights of polymers are determined by Size Exclusion Chromatography using polystyrene standards. A “polymer resin” is a monomer, oligomer or polymer which can be cured to form a cross-linked film. Preferably the polymer resins have at least two groups per molecule which are polymerizable by addition polymerization. Examples of polymerizable groups include an ethenyl group (preferably attached to an aromatic ring), benzocyclobutenes, acrylate or methacrylate groups, trifluorovinylether, cinnamate/chalcone, diene, ethoxyethyne and 3-ethoxy-4-methylcyclobut-2-enone. Preferred resins contain at least one of the following structures
where “R” groups independently are hydrogen, deuterium, C1-C30 alkyl, hetero-atom substituted C1-C30 alkyl, C1-C30 aryl, hetero-atom substituted C1-C30 aryl or represent another part of the resin structure; preferably hydrogen, deuterium, C1-C20 alkyl, hetero-atom substituted C1-C20 alkyl, C1-C20 aryl, hetero-atom substituted C1-C20 aryl or represent another part of the resin structure; preferably hydrogen, deuterium, C1-C10 alkyl, hetero-atom substituted C1-C10 alkyl, C1-C10 aryl, hetero-atom substituted C1-C10 aryl or represent another part of the resin structure; preferably hydrogen, deuterium, C1-C4 alkyl, hetero-atom substituted C1-C4 alkyl, or represent another part of the resin structure. In one preferred embodiment of the invention, “R” groups may be connected to form fused ring structures.
An arylmethoxy linkage is a linkage having at least one benzylic carbon atom attached to an oxygen atom. Preferably, the arylmethoxy linkage is an ether, an ester or a benzyl alcohol. Preferably, the arylmethoxy linkage has two benzylic carbon atoms attached to an oxygen atom. A benzylic carbon atom is a carbon atom which is not part of an aromatic ring and which is attached to a ring carbon of an aromatic ring having from 5 to 30 carbon atoms (preferably 5 to 20), preferably a benzene ring.
An “organic charge transporting compound” is a material which is capable of accepting an electrical charge and transporting it through the charge transport layer. Examples of charge transporting compounds include “electron transporting compounds” which are charge transporting compounds capable of accepting an electron and transporting it through the charge transport layer, and “hole transporting compounds” which are charge transporting compounds capable of transporting a positive charge through the charge transport layer. Preferably, organic charge transporting compounds. Preferably, organic charge transporting compounds have at least 50 wt % aromatic rings (measured as the molecular weight of all aromatic rings divided by total molecular weight; non-aromatic rings fused to aromatic rings are included in the molecular weight of aromatic rings), preferably at least 60%, preferably at least 70%, preferably at least 80%, preferably at least 90%. Preferably the resins are organic charge transporting compounds.
In a preferred embodiment of the invention, some or all materials used, including solvents and resins, are enriched in deuterium beyond its natural isotopic abundance. All compound names and structures which appear herein are intended to include all partially or completely deuterated analogs.
Preferably, the polymer resin has Mw at least 5,000, preferably at least 10,000, preferably at least 20,000; preferably no greater than 10,000,000, preferably no greater than 1,000,000, preferably no greater than 500,000, preferably no greater than 400,000, preferably no greater than 300,000, preferably no greater than 200,000, preferably no greater than 100,000. Preferably, the polymer resin comprises at least 50% (preferably at least 60%, preferably at least 70%, preferably at least 80%, preferably at least 90%) polymerized monomers which contain at least five aromatic rings, preferably at least six, preferably no more than 20, preferably no more than 15; other monomers not having this characteristic may also be present. A cyclic moiety which contains two or more fused rings is considered to be a single aromatic ring, provided that all ring atoms in the cyclic moiety are part of the aromatic system. For example, naphthyl, carbazolyl and indolyl are considered to be single aromatic rings, but fluorenyl is considered to contain two aromatic rings because the carbon atom at the 9-position of fluorene is not part of the aromatic system. Preferably, the resin comprises at least 50% (preferably at least 70%) polymerized monomers which contain at least one of triarylamine, carbazole, indole and fluorene ring systems.
Preferably, the resin comprises a first monomer of formula NAr1Ar2Ar3, wherein Ar1, Ar2 and Ar3 independently are C6-C50 aromatic substituents and at least one of Ar1, Ar2 and Ar3 contains a vinyl group attached to an aromatic ring. Preferably, the resin comprises at least 50% of the first monomer, preferably at least 60%, preferably at least 70%, preferably at least 80%, preferably at least 90%. Preferably, the resin is a copolymer of the first monomer and a second monomer of formula (I)
wherein A1 is an aromatic ring system having from 5 to 20 carbon atoms and in which the vinyl group and the —CH2OA2 group are attached to aromatic ring carbons and A2 is hydrogen or a C1-C20 organic substituent group. Preferably, A1 has five or six carbon atoms, preferably it is a benzene ring. Preferably, A2 is hydrogen or a C1-C15 organic substituent group, preferably containing no atoms other than carbon, hydrogen, oxygen and nitrogen. The monomer of formula NAr1Ar2Ar3 preferably comprises a benzyloxy linkage. In a preferred embodiment, the polymer comprises a monomer having formula (I) in which A2 is a substituent of formula NAr1Ar2Ar3, as defined above, preferably linked to oxygen via an aromatic ring carbon or a benzylic carbon. Preferably, the compound of formula NAr1Ar2Ar3 contains a total of 4 to 20 aromatic rings; preferably at least 5 preferably at least 6; preferably no more than 18, preferably no more than 15, preferably no more than 13.
In a preferred embodiment of the invention, the formulation further comprises a monomer or oligomer having Mw less than 5,000, preferably less than 3,000, preferably less than 2,000, preferably less than 1,000; preferably a crosslinker having at least three polymerizable vinyl groups.
Preferably, the polymer resins are at least 99% pure, as measured by liquid chromatography/mass spectrometry (LC/MS) on a solids basis, preferably at least 99.5%, preferably at least 99.7%. Preferably, the formulation of this invention contains no more than 10 ppm of metals, preferably no more than 5 ppm.
Preferred polymer resins useful in the present invention include, e.g., the following structures, as well as polymers comprising Monomers A, B & C, as described in the Examples.
Crosslinking agents which are not necessarily charge transporting compounds may be included in the formulation as well. Preferably, these crosslinking agents have at least 60 wt % aromatic rings (as defined previously), preferably at least 70%, preferably at least 75 wt %. Preferably, the crosslinking agents have from three to five polymerizable groups, preferably three or four. Preferably, the polymerizable groups are ethenyl groups attached to aromatic rings. Preferred crosslinking agents are shown below
Preferably, the anion is a tetraaryl borate having the formula
wherein R represents zero to five non-hydrogen substituents selected from F and CF3. Preferably, R represents five substituents on each of four rings, preferably five fluoro substituents.
Preferably, the positive aromatic ion has from seven to fifty carbon atoms, preferably seven to forty. In a preferred embodiment, the positive aromatic ion is tropylium ion or an ion having the formula
wherein A is a substituent on one or more of the aromatic rings and is H, D, CN, CF3 or (Ph)3C+(attached via Ph); X is C, Si, Ge or Sn. Preferably, X is C. Preferably, A is the same on all three rings.
Preferably, the organic Bronsted acid has pKa≤2, preferably ≤0. Preferably, the organic Bronsted acid is an aromatic, alkyl or perfluoroalkyl sulfonic acid; a carboxylic acid; a protonated ether; or a compound of formula Ar4SO3CH2Ar5, wherein Ar4 is phenyl, alkylphenyl or trifluoromethylphenyl, and Ar5 is nitrophenyl. Preferably, the TAG has a degradation temperature ≤280° C. Especially preferred acid catalysts for use in the present invention include, e.g., the following Bronsted acid, Lewis acid and TAGs.
An especially preferred TAG is an organic ammonium salt. Preferred pyridinium salts include, e.g.,
Preferably, the amount of acid is from 0.5 to 10 wt/o of the weight of the polymer, preferably less than 5 wt %, preferably less than 2 wt %.
Preferably, solvents used in the formulation have a purity of at least 99.8%, as measured by gas chromatography-mass spectrometry (GC/MS), preferably at least 99.9%. Preferably, solvents have an RED value (relative energy difference (vs. polymer) as calculated from Hansen solubility parameter using CHEMCOMP v2.8.50223.1) less than 1.2, preferably less than 1.0. Preferred solvents include aromatic hydrocarbons and aromatic-aliphatic ethers, preferably those having from six to twenty carbon atoms. Anisole, xylene and toluene are especially preferred solvents.
Preferably, the percent solids of the formulation, i.e., the percentage of monomers and polymers relative to the total weight of the formulation, is from 0.5 to 20 wt %; preferably at least 0.8 wt %, preferably at least 1 wt %, preferably at least 1.5 wt %; preferably no more than 15 wt %, preferably no more than 10 wt %, preferably no more than 7 wt %, preferably no more than 4 wt %. Preferably, the amount of solvent(s) is from 80 to 99.5 wt %; preferably at least 85 wt %, preferably at least 90 wt %, preferably at least 93 wt %, preferably at least 94 wt %; preferably no more than 99.2 wt %, preferably no more than 99 wt %, preferably no more than 98.5 wt %.
The present invention is further directed to an organic charge transporting film and a process for producing it by coating the formulation on a surface, preferably another organic charge transporting film, and Indium-Tin-Oxide (ITO) glass or a silicon wafer. The film is formed by coating the formulation on a surface, baking at a temperature from 50 to 150° C. (preferably 80 to 120° C.), preferably for less than five minutes, followed by thermal cross-linking at a temperature from 120 to 280° C.; preferably at least 140° C., preferably at least 160° C., preferably at least 170° C.; preferably no greater than 230° C., preferably no greater than 215° C.
Preferably, the thickness of the polymer films produced according to this invention is from 1 nm to 100 microns, preferably at least 10 nm, preferably at least 30 nm, preferably no greater than 10 microns, preferably no greater than 1 micron, preferably no greater than 300 nm. The spin-coated film thickness is determined mainly by the solid contents in solution and the spin rate. For example, at a 2000 rpm spin rate, 2, 5, 8 and 10 wt % polymer resin formulated solutions result in the film thickness of 30, 90, 160 and 220 nm, respectively. The wet film shrinks by 5% or less after baking and cross-linking.
A round-bottom flask was charged with N-(4-(9H-carbazol-3-yl)phenyl)-N-([1,1′-biphenyl]-4-yl)-9,9-dimethyl-9H-fluoren-2-amine (2.00 g 3.318 mmol, 1.0 equiv), 4-bromobenzaldehyde (0.737 g, 3.982 mmol, 1.2 equiv), CuI (0.126 g 0.664 mmol, 0.2 equiv), potassium carbonate (1.376 g 9.954 mmol, 3.0 equiv), and 18-crown-6 (86 mg 10 mol %). The flask was flushed with nitrogen and connected to a reflux condenser. 10.0 mL dry, degassed 1,2-dichlorobenzene was added, and the mixture was refluxed for 48 hours. The cooled solution was quenched with sat. aq. NH4Cl, and extracted with dichloromethane. Combined organic fractions were dried, and solvent was removed by distillation. The crude residue was purified by chromatography on silica gel (hexane/chloroform gradient), and gave a bright yellow solid product (2.04 g). The product had the following characteristics: 1H-NMR (500 MHz, CDCl3): δ 10.13 (s, 1H), 8.37 (d, J=2.0 Hz, 1H), 8.20 (dd, J=7.7, 1.0 Hz, 1H), 8.16 (d, J=8.2 Hz, 2H), 7.83 (d, J=8.1 Hz, 2H), 7.73-7.59 (m, 7H), 7.59-7.50 (m, 4H), 7.50-7.39 (m, 4H), 7.39-7.24 (m, 10H), 7.19-7.12 (m, 1H), 1.47 (s, 6H). 13C-NMR (126 MHz, CDCl3): δ 190.95, 155.17, 153.57, 147.21, 146.98, 146.69, 143.38, 140.60, 140.48, 139.28, 138.93, 135.90, 135.18, 134.64, 134.46, 133.88, 131.43, 128.76, 127.97, 127.81, 126.99, 126.84, 126.73, 126.65, 126.54, 126.47, 125.44, 124.56, 124.44, 124.12, 123.98, 123.63, 122.49, 120.96, 120.70, 120.57, 119.47, 118.92, 118.48, 110.05, 109.92, 46.90, 27.13.
A round-bottom flask was charged with Formula 1 (4.36 g, 6.17 mmol, 1.00 equiv) under a blanket of nitrogen. The material was dissolved in 40 mL 1:1 THF:EtOH. borohydride (0.280 g, 7.41 mmol, 1.20 equiv) was added in portions and the material was stirred for 3 hours. The reaction mixture was cautiously quenched with 1M HCl, and the product was extracted with portions of dichloromethane. Combined organic fractions were washed with sat. aq. sodium bicarbonate, dried with MgSO4 and concentrated to a crude residue. The material was purified by chromatography (hexane/dichloromethane gradient), and gave a white solid product (3.79 g). The product had the following characteristics: 1H-NMR (500 MHz, CDCl3): δ 8.35 (s, 1H), 8.19 (dt, J=7.8, 1.1 Hz, 1H), 7.73-7.56 (m, 11H), 7.57-7.48 (m, 2H), 7.48-7.37 (m, 6H), 7.36-7.23 (m, 9H), 7.14 (s, 1H), 4.84 (s, 2H), 1.45 (s, 6H). 13C-NMR (126 MHz, CDCl3): δ 155.13, 153.56, 147.24, 147.02, 146.44, 141.27, 140.60, 140.11, 140.07, 138.94, 136.99, 136.33, 135.06, 134.35, 132.96, 128.73, 128.44, 127.96, 127.76, 127.09, 126.96, 126.79, 126.62, 126.48, 126.10, 125.15, 124.52, 123.90, 123.54, 123.49, 122.46, 120.66, 120.36, 120.06, 119.43, 118.82, 118.33, 109.95, 109.85, 64.86, 46.87, 27.11.
In a nitrogen-filled glovebox, a 100 mL round-bottom flask was charged with Formula 2 (4.40 g, 6.21 mmol, 1.00 equiv) and 35 mL THF. Sodium hydride (0.224 g, 9.32 mmol, 1.50 equiv) was added in portions, and the mixture was stirred for 30 minutes. A reflux condenser was attached, the unit was sealed and removed from the glovebox. 4-vinylbenzyl chloride (1.05 mL, 7.45 mmol, 1.20 equiv) was injected, and the mixture was refluxed until consumption of starting material. The reaction mixture was cooled (iced bath) and cautiously quenched with isopropanol. Sat. aq. NH4Cl was added, and the product was extracted with ethyl acetate. Combined organic fractions were washed with brine, dried with MgSO4, filtered, concentrated, and purified by chromatography on silica. The product had the following characteristics: 1H-NMR (400 MHz, CDCl3): δ 8.35 (s, 1H), 8.18 (dt, J=7.8, 1.0 Hz, 1H), 7.74-7.47 (m, 14H), 7.47-7.35 (m, 11H), 7.35-7.23 (m, 9H), 7.14 (s, 1H), 6.73 (dd, J=17.6, 10.9 Hz, 1H), 5.76 (dd, J=17.6, 0.9 Hz, 1H), 5.25 (dd, J=10.9, 0.9 Hz, 1H), 4.65 (s, 4H), 1.45 (s, 6H). 13C-NMR (101 MHz, CDCl3): δ 155.13, 153.56, 147.25, 147.03, 146.43, 141.28, 140.61, 140.13, 138.94, 137.64, 137.63, 137.16, 137.00, 136.48, 136.37, 135.06, 134.35, 132.94, 129.21, 128.73, 128.05, 127.96, 127.76, 126.96, 126.94, 126.79, 126.62, 126.48, 126.33, 126.09, 125.14, 124.54, 123.89, 123.54, 123.48, 122.46, 120.66, 120.34, 120.04, 119.44, 118.82, 118.31, 113.92, 110.01, 109.90, 72.33, 71.61, 46.87, 27.11.
A mixture of N-(4-bromophenyl)-9,9-dimethyl-N-(4-(1-methyl-2-phenyl-1H-indol-3-yl)phenyl)-9H-fluoren-2-amine (1) (12.9 g, 20 mmol), (4-formylphenyl) boronic acid (1.07 g, 30 mmol), Pd(PPh3)4 (693 mg, 1155, 3%), 2M K2CO3 (4.14 g, 30 mmol, 15 mL H2O), and 45 mL of THF was heated at 80° C. under nitrogen atmosphere for 12 h. After cooling to room temperature, the solvent was removed under vacuum and the residue was extracted with dichloromethane. After cooling to room temperature, the solvent was removed under vacuum and then water was added. The mixture was extracted with CH2Cl2. The organic layer was collected and dried over anhydrous sodium sulphate. After filtration, the filtrate was evaporated to remove solvent and the residue was purified through column chromatography on silica gel to give light-yellow solid (yield: 75%). MS (ESI): 671.80 [M+H]+. 1H-NMR (CDCl3, 400 MHz, TMS, ppm): δ 10.03 (s, 1H), 7.94 (d, 2H), 7.75 (d, 2H), 7.64 (m, 2H), 7.55 (d, 2H), 7.41 (m, 9H), 7.23 (m, 8H), 7.09 (m, 3H), 3.69 (s, 3H), 1.43 (s, 6H).
To a solution of (2) (10 g 15 mmol) in 50 mL THF and 50 mL ethanol at 40° C., NaBH4 (2.26 g 60 mmol) was added under nitrogen atmosphere. The solution was allowed to stir at room temperature for 2 h. Then, aqueous hydrochloric acid solution was added until pH 5 and the addition was maintained for a further 30 min. The solvent was removed under vacuum and the residue was extracted with dichloromethane. The product was then obtained by remove of solvent and used for next step without further purification (yield: 95%). MS (ESI): 673.31 [M+H]+.
To a solution of (3) (9.0 g, 13.4 mmol) in 50 mL dry DMF was added NaH (482 mg, 20.1 mmol), the mixture was then stirred at room temperature for 1 h. And 4-vinylbenzyl chloride (3.05 g 20.1 mmol) was added to above solution via syringe. The mixture was heated to 50° C. for 24 h. After quenched with water, the mixture was poured into water to remove DMF. The residue was filtrated and the resulting solid was dissolved with dichloromethane, which was then washed with water. The solvent was removed under vacuum and the residue was extracted with dichloromethane. The product was then obtained by column chromatography on silica gel (yield: 90%). MS (ESI): 789.38 [M+H]+. 1H-NMR (CDCl3, 400 MHz, TMS, ppm): δ 7.59 (d, 4H), 7.48 (m, 2H), 7.40 (m, 18H), 7.22 (m, 8H), 6.71 (dd, 1H), 5.77 (d, 1H), 5.25 (d, 1H), 4.58 (s, 4H), 3.67 (s, 3H), 1.42 (s, 6H).
A mixture of 4-(3,6-dibromo-9H-carbazol-9-yl)benzaldehyde (6.00 g, 17.74 mmol), N-([1,1′-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-9H-fluoren-2-amine (15.70 g, 35.49 mmol), Pd(PPh3)3 (0.96 g), 7.72 g K2CO3, 100 mL THF and 30 mL H2O was heated at 80° C. under nitrogen overnight. After cooled to room temperature, the solvent was removed under vacuum and the residue was extracted with dichloromethane. The product was then obtained by column chromatography on silica gel with petroleum ether and dichloromethane as eluent, to provide desired product (14.8 g, yield 92%). 1H NMR (CDCl3, ppm): 10.14 (s, 1H), 8.41 (d, 2H), 8.18 (d, 2H), 7.86 (d, 2H), 7.71 (dd, 2H), 7.56-7.68 (m, 14H), 7.53 (m, 4H), 7.42 (m, 4H), 7.26-735 (m, 18H), 7.13-7.17 (d, 2H), 1.46 (s 12H).
4-(3,6-bis(4-([1,1′-biphenyl]-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amino)phenyl)-9H-carbazol-9-yl)benzaldehyde (10.0 g 8.75 mmol) was dissolved into 80 mL THF and 30 mL ethanol. NaBH4 (1.32 g 35.01 mmol) was added under nitrogen atmosphere over 2 hours. Then, aqueous hydrochloric acid solution was added until pH 5 and the mixture was kept stirring for 30 min. The solvent was removed under vacuum and the residue was extracted with dichloromethane. The product was then dried under vacuum and used for the next step without further purification.
0.45 g 60% NaH was added to 100 mL dried DMF solution of 10.00 g of (4-(3,6-bis(4-([1,1′-biphenyl]-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amino)phenyl)-9H-carbazol-9-yl)phenyl)methanol. After stirred at room temperature for 1 h, 2.00 g of 1-(chloromethyl)-4-vinylbenzene was added by syringe. The solution was stirred at 60° C. under N2 and tracked by TLC. After the consumption of the starting material, the solution was cooled and poured into ice water. After filtration and washed with water, ethanol and petroleum ether respectively, the crude product was obtained and dried in vacuum oven at 50° C. overnight and then purified by flash silica column chromatography with grads evolution of the eluent of dichloromethane and petroleum ether (1:3 to 1:1). The crude product was further purified by recrystallization from ethyl acetate and column chromatography which enabled the purity of 99.8%. ESI-MS (m/z, Ion): 1260.5811, (M+H)+. 1H NMR (CDCl3, ppm): 8.41 (s, 2H), 7.58-7.72 (m, 18H), 7.53 (d, 4H), 7.38-7.50 (m, 12H), 7.25-7.35 (m, 16H), 7.14 (d, 2H), 6.75 (q, 1H), 5.78 (d, 1H), 5.26 (d, 1H), 4.68 (s, 4H), 1.45 (s, 12H).
Under N2 atmosphere, PPh3CMeBr (1.45 g, 4.0 mmol) was charged into a three-neck round-bottom flask equipped with a stirrer, to which 180 mL anhydrous THF was added. The suspension was placed in an ice bath. Then t-BuOK (0.70 g 6.2 mmol) was added slowly to the solution, the reaction mixture turned into bright yellow. The reaction was allowed to react for an additional 3 h. After that, 4-(3,6-bis(4-([1,1′-biphenyl]-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amino)phenyl)-9H-carbazol-9-yl)benzaldehyde (2.0 g, 1.75 mmol) was charged into the flask and stirred at room temperature overnight. The mixture was quenched with 2N HCl, and extracted with dichloromethane, and the organic layer was washed with deionized water three times and dried over anhydrous Na2SO4. The filtrate was concentrated and purified on silica gel column using dichloromethane and petroleum ether (1:3) as eluent. The crude product was further recrystallized from dichloromethane and ethyl acetate with purity of 99.8%. ESI-MS (m/z, Ion): 1140.523, (M+H)+. 1H NMR (CDCl3, ppm): 8.41 (s, 2H), 7.56-7.72 (m, 18H), 7.47-7.56 (m, 6H), 7.37-7.46 (m, 6H), 7.23-7.36 (m, 18H), 6.85 (q, 1H), 5.88 (d, 1H), 5.38 (d, 1H), 1.46 (s, 12H).
To a 250 mL round bottom flask was added 7-bromobicyclo[4.2.0]octa-1,3,5-triene (10.0 g, 54.6 mmol) and 100 mL ethylene glycol. The biphasic mixture was cooled to 0° C. followed by the slow addition of solid silver(I)tetrafluoroborate (11.7 g, 60.1 mmol) to maintain a temperature about 30° C. After addition, the reaction mixture was stirred at 50° C. for 3 h. Once cooled down to room temperature, 200 ml water and 400 ml ether were added. The resulting mixture was filtered through celite. The organic layer was washed with water 3×300 ml and then dried over Na2SO4. After filtration, the filtrate was concentrated and the obtained oil was purified by column chromatography on silica gel to remove the excess ethylene glycol (yield: 70%). MS (ESI): 165.14 [M+H]+. 1H-NMR (CDCl3, 400 MHz, TMS, ppm): δ 7.28 (m, 3H), 7.14 (d, 1H), 5.08 (t, 1H), 3.76 (t, 2H), 3.72 (m, 2H), 3.44 (d, 1H), 3.11 (d, 1H).
To a solution of (5) (3.0 g, 18.3 mmol) in 50 mL dry DMF was added NaH (658 mg, 27.4 mmol), the mixture was stirred at room temperature for 1 h. And 1-(chloromethyl)-4-vinylbenzene (4.18 g, 27.4 mmol) was added to above solution via syringe. The mixture was heated to 60° C. overnight. After quenched with water, the mixture was poured into water to remove DMF. The residue was filtrated and the resulting solid was dissolved with dichloromethane, which was then washed with water. The solvent was removed under vacuum and the residue was extracted with dichloromethane. The product was then obtained by column chromatography on silica gel (yield: 82%). MS (ESI): 281.37 [M+H]+. 1H-NMR (CDCl3, 400 MHz, TMS, ppm): δ 7.38 (d, 2H), 7.30 (m, 3H), 7.23 (m, 2H), 7.14 (d, 1H), 6.74 (dd, 1H), 5.75 (d, 1H), 5.24 (d, 1H), 5.11 (t, 1H), 4.57 (s, 2H), 3.85 (t, 2H), 3.76 (t, 2H), 3.44 (d, 1H), 3.14 (d, 1H).
In a glovebox, B monomer (1.00 equiv) was dissolved in anisole (electronic grade, 0.25 M). The mixture was heated to 70° C., and AIBN solution (0.20 M in toluene, 5 mol %) was injected. The mixture was stirred until complete consumption of monomer, at least 24 hours (2.5 mol % portions of AIBN solution can be added to complete conversion). The polymer was precipitated with methanol (10× volume of anisole) and isolated by filtration. The filtered solid was rinsed with additional portions of methanol. The filtered solid was re-dissolved in anisole and the precipitation/filtration sequence repeated twice more. The isolated solid was placed in a vacuum oven overnight at 50° C. to remove residual solvent.
Monomer A has the following structure
Monomer B has the following structure:
Monomer C has the following structure
Purity and halide analyses of the anisole and tetralin used in these examples were as follows:
Molecular weights of the polymers were as follows
B-staged charge transporting polymers are formed by step-growth polymerization via [4+2] Diels-Alder reaction between BCB and styrene (Sty) in Monomers A, B & C. The polymers obtained were as follows.
To evaluate electroluminescent (EL) performances of the HTL layer in presence of acid p-dopant, the following types of OLED devices were fabricated for exploring the acid p-doping effect:
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2016/087409 | 6/28/2016 | WO | 00 |
