- Synthesis of t-butylated diphenylanthracene derivatives as blue host materials for OLED applications
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This paper describes the cost-effective synthesis and the photoluminescence of diphenylanthracene derivatives, which are found to be potential blue host materials for organic light emitting diode (OLED) technology.
- Balaganesan, Banumathy,Shen, Wen-Jian,Chen, Chin H.
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- New C2v- and chiral C2-symmetric olefin polymerization catalysts based on nickel(II) and palladium(II) diimine complexes bearing 2,6-diphenyl aniline moieties: Synthesis, structural characterization, and first insight into polymerization properties
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Four new 1,4-diaza-2,3-dimethylbutadiene ligands (Ar-N=C(CH3)-(H3C)C=NAr; Ar: 3a = 2,6=diphenylphenyl; 3b = 2,6-di(4-OCH3-phenyl)phenyl; 3c = 2,6-di(4-tert-butyl-phenyl)phenyl); 3d = 2,6-di(3,5-dimethylphenyl)phenyl as well as the palladium dichloride complexes 4a-c and methyl monochloride derivatives 5a-c were prepared, and their polymerization behavior was investigated. The corresponding nickel species 6a-c were tested for the insertion polymerization of ethene by in situ reactions of 3a-c with (DME)NiBr2. The ligands are accessible by a three-step procedure. Aryl boronic acids were prepared by Grignard reactions of substituted aryl bromides and were coupled with 2,6-dibromo aniline according to a Suzuki cross-coupling protocol to give the corresponding terphenyl anilines 2a-d. Condensation of 2,3-butanedione with the corresponding aniline afforded the formation of the diimines 3a-d. The corresponding palladium dichloride complexes 4a-c are accessible by reaction with (PhCN)2PdCl2. The structures of 4a-c could be determined by X-ray analysis. While the terphenyl complex 4a adopts a C2v-symmetry, 4c exists in a chiral C2-symmetric coordination geometry, due to the repulsive interactions of the sterically demanding tert-butylphenyl substituents of the aniline moieties. All palladium and nickel complexes are catalysts for the polymerization of ethene. However, the chiral Ni(II) complex 6c shows by far the highest polymerization activity up to 2 × 104 kg(PE) [mol (Ni) h]-1. The polyethenes obtained with the palladium methyl monochloro catalysts activated with Na[(3,5-(CF3)2C6H3)4B] and the nickel dibromo complexes activated with MAO are linear and show in the case of the Ni(II) derivatives molecular weights up to 4.5 × 106 g mol-1 (Mw/Mn ≈ 2), which can be controlled by addition of hydrogen.
- Schmid, Markus,Eberhardt, Robert,Klinga, Martti,Leskel?, Markku,Rieger, Bernhard
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- Spectroscopic and computational investigations of the thermodynamics of boronate ester and diazaborole self-assembly
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The solution phase self-assembly of boronate esters, diazaboroles, oxathiaboroles, and dithiaboroles from the condensation of arylboronic acids with aromatic diol, diamine, hydroxythiol, and dithiol compounds in chloroform has been investigated by 1H NMR spectroscopy and computational methods. Six arylboronic acids were included in the investigations with each boronic acid varying in the substituent at its 4-position. Both computational and experimental results show that the para-substituent of the arylboronic acid does not significantly influence the favorability of forming a condensation product with a given organic donor. The type of donor, however, greatly influences the favorability of self-assembly. 1H NMR spectroscopy indicates that condensation reactions between arylboronic acids and catechol to give boronate esters are the most favored thermodynamically, followed by diazaborole formation. Computational investigations support this conclusion. Neither oxathiaboroles nor dithiaboroles form spontaneously at equilibrium in chloroform at room temperature. Computational results suggest that the effect of borylation on the frontier orbitals of each donor helps to explain differences in the favorability of their condensation reactions with arylboronic acids. The results can inform the use of boronic acids as they are increasingly utilized in the dynamic self-assembly of organic materials and as components in dynamic combinatorial libraries.
- Goldberg, Alexander R.,Northrop, Brian H.
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- Transition-Metal-Free Borylation of Aryl Bromide Using a Simple Diboron Source
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In this study, we developed a simple transition-metal-free borylation reaction of aryl bromides. Bis-boronic acid (BBA), was used, and the borylation reaction was performed using a simple procedure at a mild temperature. Under mild conditions, aryl bromides were converted to arylboronic acids directly without any deprotection steps and purified by conversion to trifluoroborate salts. The functional group tolerance was considerably high. The mechanism study suggested that this borylation reaction proceeds via a radical pathway.
- Han, Min Su,Lim, Taeho,Ryoo, Jeong Yup
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p. 10966 - 10972
(2020/09/23)
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- Iron catalysis and water: A synergy for refunctionalization of boron
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A new catalytic system has been optimized to promote the conversion of boron species into others. FeCl3 associated with imidazole and water favors boron refunctionalization under mild conditions. Georg Thieme Verlag Stuttgart New York.
- Wood, John L.,Marciasini, Ludovic D.,Vaultier, Michel,Pucheault, Mathieu
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supporting information
p. 551 - 555
(2014/03/21)
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- Vaulted biaryls in catalysis: A structure-activity relationship guided tour of the immanent domain of the VANOL ligand
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The active site in the BOROX catalyst is a chiral polyborate anion (boroxinate) that is assembled in situ from three equivalents of B(OPh) 3 and one of the VANOL ligand by a molecule of substrate. The substrates are bound to the boroxinate by Hbonds to oxygen atoms O1-O3. The effects of introducing substituents at each position of the naphthalene core of the VANOL ligand are systematically investigated in an aziridination reaction. Substituents in the 4,4′- and 8,8′-positions have a negative effect on catalyst performance, whereas, substituents in the 7- and 7′-positions have the biggest impact in a positive direction. VANOL destination: The active site in the BOROX catalyst is a chiral polyborate anion (boroxinate; see figure) that is assembled in situ from three equivalents of B(OPh)3 and one of the VANOL ligand by a molecule of substrate. The effects of introducing substituents at each position of the naphthalene core of the VANOL ligand are systematically investigated in an aziridination reaction. Copyright
- Guan, Yong,Ding, Zhensheng,Wulff, William D.
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p. 15565 - 15571
(2013/11/19)
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- Metabolically stable tert-butyl replacement
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Susceptibility to metabolism is a common issue with the tert-butyl group on compounds of medicinal interest. We demonstrate an approach of removing all the fully sp3 C-Hs from a tert-butyl group: replacing some C-Hs with C-Fs and increasing the s-character of the remaining C-Hs. This approach gave a trifluoromethylcyclopropyl group, which increased metabolic stability. Trifluoromethylcyclopropyl-containing analogues had consistently higher metabolic stability in vitro and in vivo compared to their tert-butyl-containing counterparts.
- Barnes-Seeman, David,Jain, Monish,Bell, Leslie,Ferreira, Suzie,Cohen, Scott,Chen, Xiao-Hui,Amin, Jakal,Snodgrass, Brad,Hatsis, Panos
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p. 514 - 516
(2013/07/26)
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- Novel multifunctional organic semiconductor materials based on 4,8-substituted 1,5-naphthyridine: Synthesis, single crystal structures, opto-electrical properties and quantum chemistry calculation
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A series of 4,8-substituted 1,5-naphthyridines (1a-1h) have been successfully synthesised by a Suzuki cross-coupling between 4,8-dibromo-1,5- naphthyridine (4) and the corresponding boronic acids (2a-2h) in the presence of catalytic palladium acetate in yields of 41.4-75.8% and have ben well characterized. They are thermally robust with high phase transition temperatures (above 186 °C). Compounds 1b, 1e and 1f crystallized in the monoclinic crystal system with the space groups P21/c, P21/c and P21/n, respectively. All of them show the lowest energy absorption bands (λmaxAbs: 294-320 nm), revealing low optical band gaps (2.77-3.79 eV). These materials emit blue fluorescence with λmaxEm ranging from 434-521 nm in dilute solution in dichloromethane and 400-501 nm in the solid state. 4,8-Substituted 1,5-naphthyridines 1a-1h have estimated electron affinities (EA) of (2.38-2.72 eV) suitable for electron-transport materials and ionization potentials (IP) of 4.85-5.04 eV facilitate excellent hole-injecting/hole-transport materials properties. Quantum chemical calculations using DFT B3LYP/6-31G* showed nearly identical the lowest unoccupied molecular orbitals (LUMO) of -2.39 to -2.19 eV and the highest occupied molecular orbitals (HOMO) of -5.33 to -6.84 eV. These results demonstrate the 4,8-substituted 1,5-naphthyridines 1a-1h with a simple architecture might be promising blue-emitting (or blue-green-emitting) materials, electron-transport materials and hole-injecting/hole-transport materials for applications for developing high-efficiency OLEDs.
- Wang, Kun-Yan,Chen, Chen,Liu, Jin-Fang,Wang, Qin,Chang, Jin,Zhu, Hong-Jun,Li, Chong
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supporting information; experimental part
p. 6693 - 6704
(2012/09/22)
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- The synthesis, photophysical and electrochemical properties of a series of novel 3,8,13-substituted triindole derivatives
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The synthesis and properties of a series of new 3,8,13-substituted triindole derivatives 1a-1e are reported. The 3,8,13-substituted triindoles were thermally robust with high decomposition temperatures (≥405°C) and high melt transitions (219°C-373°C). Compound 5e was crystallized in the monoclinic system with the space group P21/n. These compounds showed UV-Vis absorption (λmaxAbs) in the range of 311-345 nm in DCM solution and 371-391 nm in solid state, and fluorescence maxima (λmaxEm) in the range of 394-412 nm in DCM solution and 416-461 nm in solid state. The fluorescence quantum yields ranged from 0.27 to 0.58. The estimated electron affinities (LUMO levels) and estimated ionization potential (HOMO levels) of compounds 1a-1e are 3.54-3.71 eV and 5.12-5.48 eV, respectively. Quantum chemical calculations using DFT B3LYP/6-31G showed nearly identical LUMO (-0.72 to -1.10 eV) and HOMO (-4.65 to -4.84 eV) values. These results demonstrated that the new 3,8,13-substituted triindoles are promising thermally stable host materials for organic light-emitting diodes with reasonable hole mobility.
- Zhu, Tianhao,He, Guangke,Chang, Jin,Zhao, Dongdong,Zhu, Xiaolin,Zhu, Hongjun
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p. 679 - 688
(2012/11/07)
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- Blue-light-emitting multifunctional triphenylamine-centered starburst quinolines: Synthesis, electrochemical and photophysical properties
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A series of triphenylamine-centered starburst quinolines (1a-1g) have been synthesized by Friedlaender condensation of the 4,4′,4′′- triacetyltriphenylamine (2) and 2-aminophenyl ketones (3a-3g) in the presence of catalytic sulfuric acid and characterized well. They are thermally robust with high glass transition temperatures (above 176.4 °C) and decomposition temperatures (above 406 °C). These compounds emit blue fluorescence with λEmmax ranging from 433 to 446 nm in dilute toluene solution and 461 to 502 nm in the solid-state and have a relatively high efficiency (Φu = 0.98-0.57). 1a-1g have estimated ionization potentials (IP) of 4.54 to 6.45 eV which are significantly near or higher than those of well-known electron transport materials (ETMs), including tris(8- hydroxyquinoline)aluminium (Alq3) (IP = 5.7-5.9 eV), and previously reported oligoquinolines (IP = 5.53-5.81 eV). Quantum chemical calculations using DFT B3LYP/6-31G* showed the highest occupied molecular orbital (HOMO) of -5.05 to -4.81 eV, which is close to the work function of indium tin oxide (ITO). These results demonstrate the potential of 1a-1g as hole-transporting/light-emitting/electron-transport materials and the host-materials of a dopant for hole-injecting for applications in organic light-emitting devices.
- Jiang, Peng,Zhao, Dong-Dong,Yang, Xiao-Li,Zhu, Xiao-Lin,Chang, Jin,Zhu, Hong-Jun
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scheme or table
p. 4704 - 4711
(2012/08/08)
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- Catalysts for olefin polymerization or oligomerization
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Novel iron and cobalt complexes of certain novel tricyclic ligands containing a “pyridine” ring and substituted with two imino groups are polymerization and/or oligomerization catalysts for olefins, especially ethylene. Depending on the exact structure of the ligand, and polymerization process conditions, products ranging from α-olefins to high polymers may be produced. The polymers, especially polyethylenes, are useful for films and as molding resins.
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- Synthesis and characterization of highly soluble and oxygen permeable new polyimides bearing a noncoplanar twisted biphenyl unit containing tert-butylphenyl or trimethylsilyl phenyl groups
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The two new dianhydrides, 2,2′-bis(4″-tert-butylphenyl)-4,4′,5,5′-biphenyltetracar boxylic dianhydride (BBBPAn) and 2,2′-bis(4″-trimethylsilylphenyl)-4,4′,5,5′-biphenyltetr acarboxylic dianhydride (BTSBPAn), composed of a noncoplanar twisted biphenyl unit containing tert-butylphenyl or trimethylsilyphenyl groups were prepared. Two series of new organosoluble polyimides were prepared from the dianhydride and aromatic diamines by the conventional polyamide acid reaction followed by chemical imidization as well as high-temperature one-step polymerization. The structures of polymers were confirmed by various spectroscopic techniques. The weight-average molecular weight and polydispersities of resulting polymers were in the ranges 60 400-332 400 and 1.87-3.51, respectively. The polyimides showed good solubility in various organic solvents such as chloroform and THF. The polyimides exhibited 5% weight loss at 540-550°C in nitrogen as measured by thermogravimetric analysis. The polyimides showed high Tg's and good mechanical properties. The oxygen permeability coefficient (PO2) and permselectivity of oxygen to nitrogen (PO2/PN2) of the films were in the ranges 31-110 barrer and 2.8-4.3, respectively.
- Kim, Hyung-Sun,Kim, Yun-Hi,Ahn, Seung-Kuk,Kwon, Soon-Ki
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p. 2327 - 2332
(2007/10/03)
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- Novel non-symmetric nickel-diimine complexes for the homopolymerization of ethene: Control of branching by catalyst design
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Non-symmetric diimine ligands (Ar-N=C(CH3)-(CH3)C=NAr*; Ar: 2,6-diisopropyl-phenyl; Ar*: 2,6-di(4-tert-butyl-phenyl)phenyl (4b), 2,6-di(4-OCH3)-phenyl)phenyl (4c)) were synthesized and converted in-situ into the corresponding nickel dibromo complexes (5b, c) by reaction with (DME)NiBr2. The complexes were activated for ethene polymerization by treatment with MAO at ambient temperature. The resulting high molecular weight polymer products (Mw > 4.0 × 106 g mol-1) have a branched microstructure (predominantly methyl groups), as indicated by 13C NMR spectroscopy. The degree of branching can be controlled by a proper choice of the 2,6-diphenyl modified aniline moieties resulting in melting transitions ranging from 92 - 130°C.
- Schmid, Markus,Eberhardt, Robert,Kukral, Jürgen,Rieger, Bernhard
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p. 1141 - 1146
(2007/10/03)
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- A borazaaromatic analogue of isophthalic acid
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A diboradiazaaromatic-2,7-di-tert-butyl-5,9-dihydroxy-5,9-dibora-4,10-diazapyrene- 4,10-diium-5,9-diuide- which is a structural analogue of isophthalic acid has been designed and synthesised. This compound is capable of spontaneous dehydration in solution to form linear oligoanhydrides. These oligoanhydrides can be readily hydrolysed to the starting diboradiazaaromatic under appropriate conditions. This unusual reactivity is mirrored in the solid-state behaviour of 2,7-di-tert-butyl-5,9-dihydroxy-5,9-dibora-4,10-diazapyrene-4,10-diium-5,9-diuid e. A complex network of hydrogen bonds present in the solid-state structure of the borazaaromatic serve to facilitate a facile solid-state dehydration reaction, once again forming oligoanhydrides of molecular weight greater than 3000 Da.
- Ashton, Peter R.,Harris, Kenneth D.M.,Kariuki, Benson M.,Philp, Douglas,Robinson, James M.A.,Spencer, Neil
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p. 2166 - 2173
(2007/10/03)
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- Propanoic acid derivatives
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Propanoic acid derivatives of formula (1) are described: Ar—X1—Ar1—Z—R??(1) in which Ar is a nitrogen base containing group; X1is linker atom or group; Ar1is an optionally substituted 5- or 6-membered nitrogen-containing aromatic or non-aromatic monocycle; Z is a group —CH(R13)CH2— [in which R13is an optionally substituted aliphatic, cycloaliphatic, heteroaliphatic, heterocycloaliphatic, aromatic or heteroaromatic group], —C(R12a)(R13)—CH(R12b)— [in which R12aand R12btogether with the carbon atoms to which they are attached form a C3-7cycloalkyl group] or C(R13)═CH—; R is a carboxylic acid (—CO2H) or a derivative or biostere thereof; and the salts, solvates, hydrates and N-oxides thereof. The compounds are able to inhibit the binding of αVintegrins to their ligands and are of use in the prophylaxis and treatment of immune or inflammatory disorders.
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- PHENYL SULFONAMIDE ENDOTHELIN ANTAGONISTS
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Compounds of the formula STR1 inhibit the activity of endothelin. The symbols are defined as follows: R 1, R 2 and R. sup.3 are each independently(a) hydrogen, except that R. sup.1 is other than hydrogen;(b) alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with Z 1, Z 2 and Z. sup.3 ;(c) halo;(d) hydroxyl;(e) cyano; (f) nitro; (g)--C(O)H or--C(O)R 6 ;(h)--CO 2 H or--CO 2 R 6 ; (i)--SH,--S(O) n R 6,--S(O) m--OH,--S(O) m--OR 6,--O--S(O) m--R 6,--O--S(O) m OH or--O--S(O) m--OR. sup.6 ;(j)--Z. sup.4--NR 7 R 8 ; or (k)--Z 4--N(R 11--Z 5--NR 9 R 10 ; and the remaining symbols are as defined in the specification.
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