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91.
以氯甲基杂环聚醚酮(CMPPEK)为原料,加入三乙胺进行铵化,并分别加入二乙烯三胺(DETA)和二乙胺(DEA),生成的仲胺基(或叔胺基)与邻近分子链氯甲基团进行自交联.经过制膜和离子交换反应,制备了DETA自交联杂萘联苯聚芳醚阴离子交换膜(DETA-QPPEK-OH)和DEA自交联杂萘联苯聚芳醚阴离子交换膜(DEA-QPPEK-OH).采用傅里叶变换红外(FTIR)光谱对制备自交联膜的化学结构进行表征.研究了DETA-QPPEK-OH和DEA-QPPEK-OH膜的理化性质,结果表明前者具有较低吸水率和更低溶胀度.通过研究DETAQPPEK-OH和DEA-QPPEK-OH膜的离子传导率随温度的变化规律,结果表明在80°C时其离子传导率分别达到0.060和0.028 S cm-1,表明本文制备的自交联膜具有较高离子传导率.此外还通过热重分析(TGA)对两类自交联膜的热稳定性进行了研究. 相似文献
92.
合理构筑了3个具有固态自旋交叉特性的亚铁四面体笼状化合物1~3。单晶X射线衍射分析证实了化合物是由6个咪唑席夫碱配体和4个亚铁离子组装形成的边导向封顶胶囊结构。金属中心占据四面体的顶点,而配体组成了四面体的边。这些笼状化合物的内部空腔被咪唑基团环绕,而外部则被取代苯环包围。一个阴离子客体被限域在笼状化合物空腔内,并与笼状化合物主体产生较强的相互作用。当在笼状化合物的乙腈溶液中加入卤素离子(Cl-和Br-)时,溶液的颜色和MLCT峰强度会发生明显变化,表明亚铁四面体笼状化合物的自旋状态由低自旋向髙自旋发生了转换。 相似文献
93.
94.
A universal and efficient Cu(I)-catalyzed synthesis of aryl and alkyl trifluoromethyl sulfides has been developed. In this catalytic system, S-aryl or S-alkyl sulfothioate (I or II) proved to be the key intermediate. Substrates bearing groups of I, Br, Cl, OTs, and OMs on the aryl carbon and no matter electron-withdrawing and electron-donating substitutions on the aromatic ring could afford good to excellent yields. 相似文献
95.
The organocatalytic sulfenylation of α-nitroesters mediated by diaryl-l-prolinols was developed. A range of α-sulfenylated α-nitroesters were obtained in good yields with moderate to good enantioselectivities. 相似文献
96.
《Tetrahedron》2014,70(21):3447-3451
Copper(II) catalyzed cross-dehydrogenative coupling of cyclic benzylic ethers with a variety of simple carbonyl compounds mediated by Na2S2O8 is developed. The scope of carbonyl components is broad, including simple aldehydes as well as ketones. The use of Na2S2O8 as the oxidant for the CDC reaction is attractive based on economical and environmental factors. 相似文献
97.
Four cholate-based pyridinium compounds were synthesized and their binding abilities toward unmodified amino acids were investigated by UV spectroscopy and fluorescence emission spectroscopy. Studies revealed that the recognition process involved hydrogen bonding, electrostatic force, and π–π interaction. The receptor 4a was found to recognize l-tryptophan specifically, and the complex was studied by 1H NMR spectroscopy. The receptors 4b and 4c showed very little recognition ability toward l-tryptophan, indicating the important role of the benzyl group at pyridinium ring. 相似文献
98.
Several 8-8-coupled tetraarylfuran-type oligostilbenes were prepared through FeCl3·6H2O-catalyzed regioselective oxidative couplings of protected resveratrol precursors. The global deprotection of the coupling dimers in a one-pot reaction yielded (±)-pallidol instead of the targets (±)-restrytisol B and (±)-tricuspidatol A. 相似文献
99.
A new multireference perturbation series is derived based on the Rayleigh–Schrödinger perturbation theory. It is orbitally invariant. Its computational cost is comparable to the single reference Møller–Plesset perturbation theory. It is demonstrated numerically that the present multireference second‐ and third‐order energies are size extensive by two types of supermolecules composed of H2 and BH monomers. Spectroscopic constants of as well as the ground state energies of H2O, NH2, and CH2 at three bond lengths have been calculated with the second multireference perturbation theory. The dissociation behaviors of CH4 and HF have also been investigated. Comparisons with other approximate theoretical models as well as the experimental data have been carried out to show their relative performances. © 2013 Wiley Periodicals, Inc. 相似文献
100.
Tong Shen Rong Xiao Qiong Wang Lijuan Yang Nong Wang 《Journal of Dispersion Science and Technology》2014,35(3):435-440
The absorption spectrum of Sudan red III (SR) in oil solutions and a series of O/W microemulsion with surfactant sodium dodecyl sulfate (SDS) has been determined by the UV-Vis spectrophotometer. We found that an association interaction existed between the stain SR and anionic surfactant SDS in water/mixed oil/SDS microemulsions. By measuring the absorbance of Sudan red in a series of microemulsions which has different R values and using the appropriate association models to analyze the experimental data, we obtain the association constants of SR and SDS, and the values of thermodynamics functions of associationΔr G m has also been calculated from the association constants. 相似文献