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151.
Koji Takagi Tsuyoshi Nakagawa Hidenobu Takao 《Journal of polymer science. Part A, Polymer chemistry》2010,48(1):91-98
Two arylenevinylene compounds bearing the cyano group at α‐position ( 6 ) and β‐position ( 9 ) from the dialkoxylphenylene unit were synthesized, in which the molecular termini were functionalized with 3‐bromocarbazole. The Suzuki coupling copolymerization of these compounds with 1,4‐bis[(3′‐bromocarbazole‐9′‐yl)methylene]‐2,5‐didecyloxybenzene and 9,9‐dihexylfluorene‐2,7‐bis(boronic acid) was carried out to obtain copolymers ( cp67 and cp97 ) containing the cyano‐substituted arylenevinylene fluorophore of 7 mol %. Model compounds ( 6 ′ and 9 ′) corresponding to the arylenevinylene fluorophore were also prepared. The UV spectra of copolymers resembled that of homopolymer hp with no arylenevinylene segment in both CHCl3 solution and thin film. The emission maxima of copolymers in CHCl3 (394 nm) agreed with that of homopolymer indicating that the emission bands originated from the carbazole‐fluorene‐carbazole segment. The emission maximum wavelength of copolymer cp67 in thin film (477 nm) indicated fluorescence from the cyano‐substituted arylenevinylene fluorophore because of the occurrence of fluorescence resonance electron transfer. In contrast, copolymer cp97 showed fluorescence at 528 nm to suggest the formation of a new emissive species such as a charge‐transfer complex (exciplex). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 91–98, 2010 相似文献
152.
《应用有机金属化学》2017,31(12)
The amino acid arginine was used to modify the surface of graphene oxide nanosheets and then nickel‐substituted cobalt ferrite nanoparticles were supported on those arginine‐grafted graphene oxide nanosheets (Ni0.5Co0.5Fe2O4@Arg–GO). The prepared Ni0.5Co0.5Fe2O4@Arg–GO was characterized using flame atomic absorption spectroscopy, inductively coupled plasma optical emission spectrometry, energy‐dispersive spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, Raman spectroscopy, X‐ray diffraction, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The application of Ni0.5Co0.5Fe2O4@Arg–GO as a catalyst was examined in a one‐pot tandem oxidative cyclization of primary alcohols with o ‐phenylenediamine to benzimidazoles under aerobic oxidation conditions. The results showed that 2‐phenylbenzimidazole derivatives were successfully achieved using Ni0.5Co0.5Fe2O4@Arg–GO nanocomposite catalyst via the one‐pot tandem oxidative cyclization strategy. 相似文献
153.
Silica chloride catalysted one pot cyclocondensation of aldehydes,ethyl acetoacetate and phenyl hydrazine leading to substituted pyrazoles has been reported. 相似文献
154.
O. P. Singh A. P. Singh Ajai Kumar L. S. Yadav J. S. Yadav 《Journal of Chemical Sciences》1988,100(5):441-446
Giambiagi’s definition of oxidation number of an atom in a molecule has been applied successfully in theab initio SCF theory to calculate oxidation numbers using STO-3G and 4–31G basis sets for some substituted benzenes involving -F, -OH,
-CH3 and -NH2 as substituents. The present study suggests that the oxidation numbers also seem to be indicative of their orientational
behaviour like the net atomic charges. 相似文献
155.
Two new solid-phase syntheses of substituted pyrazoles are described. The first includes supporting an o-hydroxyacetophenone on Merrifield resin, Vilsmeier-Haack formylation on the methyl group and cyclization with a substituted hydrazine to afford a pyrazole ring with two diversity centers. The second starts from o-hydroxyacetophenone supported on Wang resin, which undergoes a Claisen condensation with a carboxylic acid ester to yield a 1,3-dicarbonyl compound that cyclizes to a pyrazole using a hydrazine. Both methods have been used to synthesize two small pyrazole libraries. 相似文献
156.
Fluorine substituted Li1.27Cr0.2Mn0.53O2 electrode, prepared by sol–gel method, was investigated in the present work. Thermal analysis was done on this cathode material
and found to be thermally stable with a loss of weight near 300 °C. Influence of fluorine substitution on the structural and
electrochemical properties of the Li1.27Cr0.2Mn0.53O2 electrode was studied by X-ray diffraction (XRD) and field emission scanning electron microscope. XRD pattern of the fluorine-doped
Li1.27Cr0.2Mn0.53O2 cathode material quenched at 900 °C indicates a phase pure material. The charge–discharge profile of the prepared cathode
material showed that the fluorine substitution for oxygen in the cathode material resulted in improved capacity retention.
Paper presented at the Third International Conference on Ionic Devices (ICID 2006), Chennai, Tamilnadu, India, December 7–9,
2006. 相似文献
157.
Kenjiro Onimura Mieko Matsushima Munetoshi Nakamura Tatsuya Tominaga Kazuhiro Yamabuki Tsutomu Oishi 《Journal of polymer science. Part A, Polymer chemistry》2011,49(16):3550-3558
2,3‐Diaryl substituted maleimides as model compounds of conjugated maleimide polymers [poly(RMI‐alt‐Ar) and poly(RMI‐co‐Ar)] were synthesized from 2,3‐dibromo‐N‐substituted maleimide (DBrRMI) [R= cyclohexyl (DBrCHMI) and n‐hexyl (DBrHMI)] and aryl boronic acid using palladium catalysts. To clarify structures of conjugated polymer containing maleimide units at the main chain, 13C NMR spectra of 2‐aryl or 2,3‐diaryl substituted maleimides were compared with those of N‐substituted maleimide polymers. Copolymers obtained with DBrRMI via Suzuki‐Miyaura cross‐coupling polymerizations or Yamamoto coupling polymerizations were dehalogenated structures at the terminal end. This dehalogenation may contribute to the low polymerizability of DBrRMIs. On the other hand, the π‐conjugated compounds showed high solubility in common organic solvents. The N‐substituents of maleimide cannot significantly affect the photoluminescence spectra of 2,3‐diaryl substituted maleimides derivatives. The fluorescence spectra of poly(RMI‐alt‐Ar) and poly(RMI‐co‐Ar) varied with N‐substituents of the maleimide ring. When exposed to ultraviolet light of wavelength 352 nm, a series of 1,4‐phenylene‐ and/or 2,5‐thienylene‐based copolymers containing N‐substituted maleimide derivatives fluoresced in a yellow to blue color. It was found that photoluminescence emissions and electronic state of π‐conjugated maleimide derivatives were controlled by aryl‐ and N‐substituents, and maleimide sequences of copolymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
158.
Qiang Peng Xiangju Liu Yuancheng Qin Dan Zhou Jun Xu 《Journal of polymer science. Part A, Polymer chemistry》2011,49(20):4458-4467
A new series of low‐bandgap copolymers based on electron‐accepting thieno[3,4‐b]pyrazine (TPZ) and different electron‐donating aza‐heteroaromatic units, such as carbazole (CZ), dithieno[3,2‐b:2′,3′‐d]pyrrole (TPR) and dithieno[3,2‐b:2′,3′‐e]pyridine (TPY), have been synthesized by Suzuki or Stille coupling polymerization. The resulting copolymers were characterized by NMR, elemental analysis, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. UV–vis absorption and cyclic voltammetry measurements show that TPZ‐based copolymer with TPR has the best absorption due to the strongest intramolecular charge transfer effect and smallest bandgap. The basic electronic structure of D‐A model compounds of these copolymers were also studied by density functional theory (DFT) calculations. The conclusion of calculation agreed also well with the experimental results. The polymer solar cells (PSCs) based on these copolymers were fabricated with a typical structure of ITO/PEDOT:PSS/copolymer:PC71BM/Ca/Al under the illumination of AM 1.5G, 100 mW cm?2. The performance results showed that TPZ‐based copolymer with TPR donor segments showed highest efficiency of 1.55% due to enhanced short‐circuit current density. The present results indicate that good electronic, optical, and photovoltaic properties of TPZ‐based copolymers can be achieved by just fine‐tuning the structures of aza‐heteroaromatic donor segments for their application in PSCs. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
159.
The title complex,[Ag2(L1)2(Pyr)·2.5H20]1(L1=6-amino-1-naphthalenesulfonate anion,Pyr=pyrazine),has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1,with a=7.339(5),b=13.105(5),c=14.097(5)(A),α=84.377(5),β=76.921(5),γ=79.628(5)°,V= 1296.7(11)(A°)3,C48H50Ag4N8O17S4,Mr =1570.68,Z=1,Dc=2.011 g/cm3,/μ= 1.732 mm-1,F(000)=782,S=1.148,the final R=0.0436 and wR=0.1181 for 4130 observer reflections(I>20(I)).Compound 1 shows a rare one- dimensional(1D)double chain, and the chains are further connected through secondary bonding,hydrogen bonds, and π-π interactions to generate a three-dimensional(3D)supramolecular structure.The luminescent property of 1 was also studied in the solid state at room temperture. 相似文献
160.