共查询到20条相似文献,搜索用时 0 毫秒
1.
The Langmuir monolayer properties of lower rim aromatically substituted calix[4]arenes, 5,11,17,23-tetra-tert-butyl-25,27-bis(2-naphth-1'-ylacetylaminoethoxy)-26,28-dihydroxylcalix[4]arene (BNAEC), 5,11,17,23-tetra-tert- butyl-25,27-bis(2-benzoylamino ethoxy)-26,28-dihydroxylcalix[4]arene (BBAEC) and 5,11,17,23-tetra-tert-butyl- 25,27-bis(2-cinnamoylaminoethoxy)-26,28-dihydroxylcalix[4]arene (BCAEC), have been studied. Film balance measurements and Brewster angle microscopy (BAM) observation demonstrate that all the compounds can form Langmuir monolayers with different molecular limiting areas. BNAEC or BBAEC monolayer is able to form condensed domains during compression, while BCAEC monolayer can never form condensed domain. BNAEC monolayer is more readily to form condensed domain than BBAEC monolayer. Moreover, BNAEC monolayer can form the total condensed phase during compression even when T=28℃, while BBAEC monolayer can not when T 〉 10 ℃. The results imply that different lower rim aromatic substitutions affect essentially the intermolecular interaction and molecular packing in the monolayer at air/water interface. 相似文献
2.
3.
E. A. Petrushkina D. V. Khomishin N. E. Mysova A. V. Orlinkov V. N. Kalinin A. B. Ponomarev I. A. Godovikov Ya. V. Zubavichus A. A. Veligzhanin 《Moscow University Chemistry Bulletin》2007,62(5):276-280
2-Butyl-4,9-decadienoic and 2-butyl-4,9-dimethyl-4,9-decadienoic acids, structural isomers of 2-cyclohexylgeranylacetic acid, which is an active component of the wound healing ointment cygerol, have been synthesized. Hydrocarbon chains C10 have been obtained by the one-pot method of formation of long-chain hydrocarbons, namely, by the telomerization reaction of 1,3-dienes with nucleophiles catalyzed by palladium complexes. A heterogeneous palladium-zeolite catalyst has been used for the first time in telomerization of isoprene with piperidine. 相似文献
4.
Succinoylation, acetylation and nitration of 4-methyldibenzothiophene yields 2-substituted products. Bromination however, gave 3-bromo-4-methyldibenzothiophene as the major product along with a small amount of the 2-isomer. The bromo-compounds were used to prepare related derivatives via lithium exchange. 4-Methyldibenzothiophene 5,5-dioxide was also shown to nitrate in the 3-position. The structures of the derivatives were determined by NMR analyses. An alternative synthesis of 4-methyldibenzothiophene is described. 相似文献
5.
A new family of organic semiconducting materials (1-4) integrating the structural components of thiophene and fluorene into a single molecular entity was synthesized and characterized. Optical and electrochemical properties of these previously unknown 4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene-4,9-dione derivatives were studied in detail. These materials possess unique optical properties with the longest wavelength absorption maxima around 500-800 nm, which gradually reached a saturation limit with the total number of thiophene units approaching eight. They also display dramatic change in the redox properties with increasing conjugation chain lengths. A thin film of oligomer 3 prepared by a solution-casting method showed a well-ordered solid-state structure according to X-ray diffraction analysis. 相似文献
6.
The reaction rate of nucleophilic substitution can be dramatically enhanced by microwave irradiation using the ionic liquid [Bmim]BF4 as a solvent. Nucleophilic reagents (anilines, thiophenol) react with ethoxymethylene isopropylidene malonate to give corresponding products in 5–10 min in good yields. 相似文献
7.
8.
ThefindingsthatC6ocanreactwithmetalsanddonorspeciestoformchargetransfersalts,suchassuperconductorK3C6o[l]andchargetransfercomplexeslikeferromagnetreductionpotentials).Tothebestofourknowledge,however,thereareonlyC6oF48[3],3quirone-typemethanofullerene[4],andthreesingly[5,6]-bridgedcompounds[5]whosereductionpotentialsaremorepositivethanthatofC6o'Here,wereporttheelectrochemistryandinsituAIRabsorptionspectroscopyofanewC6oderivative(la),synthesizedinourlaboratory,whosereductionpotentialsaremore… 相似文献
9.
An aromatic nucleophilic substitution reaction of phenylethers with primary amines is described. This reaction, promoted by electron-attracting groups on the benzene ring, fast and simple to perform, leads to substituted anilines in high yields. 相似文献
10.
11.
Jie Chen Rong Ji Dai Bin Tong Sheng Yuan Xiao Wei Wei Meng 《中国化学快报》2007,18(1):10-12
The reduction of 4-nitrophenol catalyzed by nitroreductase in the presence of NADH was investigated in this paper.4-Amino- phenol and 4-bydroxylamino-phenol were found in the reductive products.The relationship between reaction time and the reductive ratio were studied.The similar reducing ratios of 4-nitrophenol were obtained under aerobic and anaerobic conditions.The results indicated that an oxygen-insensitive reaction was proceeded in the reduction of 4-nitrophenol and nitroreductase was an oxygen- insensitive enzyme.The reductive products of 4-nitrophenol were determined by HPLC and MS. 相似文献
12.
Dr. Yao Xiao Yan-Fang Zhu Dr. Wei Xiang Dr. Zhen-Guo Wu Yong-Chun Li Jing Lai Shi Li Dr. Enhui Wang Zu-Guang Yang Chun-Liu Xu Prof. Ben-He Zhong Prof. Xiao-Dong Guo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(4):1507-1511
Demands for large-scale energy storage systems have driven the development of layered transition-metal oxide cathodes for room-temperature rechargeable sodium ion batteries (SIBs). Now, an abnormal layered-tunnel heterostructure Na0.44Co0.1Mn0.9O2 cathode material induced by chemical element substitution is reported. By virtue of beneficial synergistic effects, this layered-tunnel electrode shows outstanding electrochemical performance in sodium half-cell system and excellent compatibility with hard carbon anode in sodium full-cell system. The underlying formation process, charge compensation mechanism, phase transition, and sodium-ion storage electrochemistry are clearly articulated and confirmed through combined analyses of in situ high-energy X-ray diffraction and ex situ X-ray absorption spectroscopy as well as operando X-ray diffraction. This crystal structure engineering regulation strategy offers a future outlook into advanced cathode materials for SIBs. 相似文献
13.
一氧化碳还原法制备磷酸铁锂—反应机理和动力学 总被引:1,自引:0,他引:1
由CO还原FePO4和LiOH前驱体合成LiFePO4正极材料,应用XRD、SEM表征材料结构和形貌、充放电曲线测试电化学性能.结果表明,LiOH过量5%合成的LiFePO4样品颗粒度约200 nm,包覆碳后LiFePO4电极0.1C放电容量可达158 mAh/g.高温现场XRD对该合成反应作实时监控,借助时间分辨图谱分析,检测出Li3Fe2(PO4)3中间物.动力学研究表明成核与生长是该合成过程的速控步骤,反应活化能为89.44 kJ/mol. 相似文献
14.
Qixing Zhou Zhangbin Su Yidan Tang Li Ai Dr. Gengtao Fu Dr. Zexing Wu Prof. Dongmei Sun Prof. Yawen Tang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(24):6226-6232
The development of effective and affordable electrocatalysts for the oxygen reduction reaction (ORR) is critical for the renewable-energy technologies. Here, we present a new manganese iron oxide (MnFeO2) as a cost-effective material for the ORR with Pt-like electrochemical properties. Pyrolysis of hybrid agar hydrogel on NaCl nanocrystals furnishes a unique structure in which the active MnFeO2 particles are uniformly immobilized in the nitrogen-doped porous carbon aerogels (MnFeO2/NPC). Nitrogen-doped carbon is introduced to construct porous mass-transfer channels and reduce self-aggregation of the MnFeO2 particles. It is found that the formation of the MnFeO2 phase greatly depends on the pyrolysis temperature. Benefiting from the synergy of MnFeO2 and NPC, the MnFeO2/NPC can actually be as good as the Pt/C catalyst for the ORR, with an onset-potential of 0.98 V and a half-wave potential of 0.86 V, combined with demonstrating a superior stability and tolerance to methanol. 相似文献
15.
16.
3-Acetyltropolone ( 1 ) reacted with 2-methoxybenzaldehyde ( 2a ) in the presence of ethyl orthoformate and perchloric acid to afford 2-(2-methoxyphenyl)-4,9-dihydrocyclohepta[b]pyran-4,9-dione ( 3a ). The reactions with 3,4-dimethoxybenzaldehyde ( 2b ), vanillin ( 2c ), and piperonal ( 2d ) gave respectively the corresponding products 3b-d . The reaction with benzaldehyde ( 2e ) gave uncyclized 3-cinnamoyltropolone ( 4 ). 相似文献
17.
Arylselenolate Ions which were produced through reductive cleavage of Se-Se bond in diaryl diselenide undergo nucleophilic substitution on aromatic rings and a series of new unsymmetrical diaryl selenides were synthesized. 相似文献
18.
19.
《Journal of Coordination Chemistry》2012,65(1-4):345-350
Abstract The otherwise very fast CO substitution of Co4(CO)12 by P(OMe)3 and P(OEt)3 in aprotic solvents, affording phosphite-monosubstituted products was retarded by the use of CHCI3 as solvent. This made it possible to investigate these reactions by conventional methods. Kinetic data were obtained by following changes in IR spectra during reaction. The rates show predominantly a ligand-dependent pathway, with the usual two-term rate law, rate = (k1 + k2 [P(OR)3])C4(CO)12. It is suggested that the rates are retarded in protonic solvents by decreasing the nucleophilicity of phosphites due to a hydrogen bonding interaction between the H atom of CHCI3 and the O atoms of the ligands. 相似文献
20.
Bo Huang Hirokazu Kobayashi Tomokazu Yamamoto Takaaki Toriyama Syo Matsumura Yoshihide Nishida Katsutoshi Sato Katsutoshi Nagaoka Masaaki Haneda Wei Xie Yusuke Nanba Michihisa Koyama Fenglong Wang Shogo Kawaguchi Yoshiki Kubota Hiroshi Kitagawa 《Angewandte Chemie (International ed. in English)》2019,58(8)