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981.
982.
一维链状配位聚合物[M(H2bpb)(H2O)4](SO4)2·6H2O[M=Zn(Ⅱ),Cu(Ⅱ)]的合成及晶体结构表征 总被引:3,自引:0,他引:3
设计并合成了一个含吡啶基团的柔性配体:N,N′-Bis(3-pyridylmethyl)-1,4-benzenedimethylamine(bpb)。通过bpb与硫酸锌及硫酸铜反应得到了两个新型具有一维链状结构的配位聚合物:[M(H2bpb)(H2O)4](SO4)2·6H2O[M=Zn(Ⅱ) 1,Cu(Ⅱ) 2]。X-射线晶体结构测定表明,这两个 相似文献
983.
1-苯基-3-甲基-4-(6-氢-4-甲基氨基-5-硫杂-2,3-吡嗪)-吡唑啉酮的合成与晶体结构 总被引:1,自引:0,他引:1
通过1-苯基-3-甲基-4-氯乙酰基-吡唑啉酮-5 (PMCP) 和4-甲基氨基硫脲 (MTSC) 缩合, 形成了一种新的双杂环化合物 (PMCP-MTSC)。利用元素分析与单晶X-射线衍射进行了表征。 该化合物(C14H15N5OS)属单斜晶系, P21 空间群, 晶体学参数为 a = 7.634(1), b = 11.639(2), c = 8.150(2) ? ?= 98.13(1), V = 716.9(2) ?, Z = 2, Dc = 1.396 g/cm3, (MoKa) = 0.232 mm-1, F(000) = 316, Mr = 301.37。结构由直接法解出,共收集3114个衍射点,其中I > 2(I)的独立衍射点有2453个,用全矩阵最小二乘法修正,最终偏离因子:R = 0.0294, wR = 0.0738。结构分析表明: 该化合物以酮式存在,分子间通过氢键作用(N(5)H…O)连接起来并形成一维链状结构。 相似文献
984.
以硫醇为螯合剂, 在溶剂热条件下合成了两种层状硫代亚碲酸盐KAgTeS3 (1)和RbAgTeS3 (2). X射线单晶解析表明, 1和2是类质同晶化合物. 在晶体结构中, 银硫四面体通过共用顶点形成无限的平行链, 在相邻链中银硫四面体取向相反, 这些链与链由三角锥配位的碲互相连接形成阴离子层状结构, 阳离子在阴离子层间. 1的结晶学数据为: Mr=370.75, P21/c, a=0.73639(6) nm, b=1.06468(8) nm, c=0.85203(6) nm, β=106.4640(10)°, V=0.64062(8) nm3, Z=4, R(F)=4.44%, wR(F2)=11.66%. 2的结晶学数据: Mr=417.12, P21/c, a=0.75531(12) nm, b=1.07076(7) nm, c=0.8583(2) nm, β=106.497(6)°, V=0.66558(19) nm3, Z=4, R(F)=6.00%, wR(F2)=15.43%. DSC及紫外-可见漫反射光谱研究表明, 这两种化合物为半导体, 并具有很好的热稳定性. 相似文献
985.
Reinhard Haase Dorit S. Meinhold Berthold Thomas Edwin Weber Gerd Rheinwald 《Structural chemistry》2002,13(5-6):471-477
The crystal structures of inclusion compounds of 3,3-bis(9-hydroxy-9-fluorenyl)-2,2-binaphthyl host (1) and its chloro (2) or bromo (3) derivatives substituted in 2,7-positions of the fluorene units with acetone guests (1A–3A) were determined by X-ray studies as well as by 1H-CRAMPS solid-state NMR. Using this NMR technique allows identification of differently bound guest molecules due to their different chemical shifts caused by the influence of the ring current effects of the host aryl units. 相似文献
986.
P. Favard J. P. Lechaire M. Maillard N. Favard P. Andreazza F. Lefaucheux M. C. Robert 《Colloid and polymer science》1992,270(6):584-589
Silica gel provides a useful medium for crystal growth; solution growth is confined to pores left free by the polymer during its development. All growth steps depend on the gel structure, which is not completely known for crystal growth conditions. Therefore, a three-dimensional (3-D) visualization has been performed for two TMOS aqueous gels, which are rather fragile: the quick-freeze, deep-etching, rotary-replication method has been applied for sample preparation. An original surface labeling technique has been used for surface recognition. The results concern the distribution of macropores that are responsible for crystal nucleation; micropores whose total volume is larger have not been visualized due to the limits of the method. These results are discussed in comparison with previous data performed by light scattering. 相似文献
987.
M. J. Whitcombe A. Gilbert G. R. Mitchell 《Journal of polymer science. Part A, Polymer chemistry》1992,30(8):1681-1691
The syntheses of three methacrylate monomers with cinnamate ester side-chains and of a further monomer with a corresponding cinnamide side-chain are described. Two of the monomers, with isomeric structures, were thermotropic liquid crystals. Although the clearing points were very similar the crystal melting points differed by 8°C. One compound also exhibited a monotropic smectic phase, behavior not shown by its isomer. The other two monomers were not liquid crystalline. The monomers were polymerized by free radical polymerization, both as homopolymers and as copolymers with methyl methacrylate. In the case of one of the mesogenic ester monomers, copolymers with a cyanophenyl benzoate monomer were also prepared. Three of the four monomers formed thermotropic liquid crystalline homopolymers and the copolymers with the benzoate monomer were also liquid crystalline. The monomers were considered as photoactive components of polymeric liquid crystals. As a preliminary investigation of their photochemistry, copolymers with methyl methacrylate were prepared and irradiated in solution with a broad-band source. Under these conditions two of the materials show a facile photo-Fries rearrangement of the aryl cinnamate ester group. © 1992 John Wiley & Sons, Inc. 相似文献
988.
CMAO Jiang-Gao 《结构化学》1998,(5)
1INTR0DUCTI0NLanthanidecarboxylatecomplexeshavebeenwidelystudiedt1iandm0starefoundtoexhibitavarietyofdimericorinfinitechainstructures.Recentstudiesinourlaboratoryhavedem0nstratedthattheprototypetertiaryaminebetaine(Me,N CHzC0z-)anditsderivativesareusefulinthegenerationoflanthanidecarb0xylate-likecomplexeswithnewstructuralfeaturesduetotheiroverallchargeneutralityandpossibleinclusionofvariouskindsofcounteranionsinthestructuret2~4i.Thelan-thanidecomplexesisolatedsofarhavebeenfoundtobemononu… 相似文献
989.
Complexes have been prepared by treatment ofn-decylammonium beidellite with mixtures ofn-decanol andn-tetradecanol with different concentrations. Measurements of the basal spacings of the obtained complexes have been performed in a wide range of temperatures. Three different bilayer phases have been established between (20 and 70°C: the
i(C10) phases (=bilayers ofn-decyl chains); the
i(C10/C14) phases (=mixed bilayers ofn-decyl andn-tetradecyl chains in molar ratio approximately 1:1) and the
i(C14) phases (=bilayer ofn-tetradecy 1 chains with then-decylammonium ions included). In all bilayer phases the chains stand perpendicular to the silicate interfaces. In definite concentration ranges two of the phases coexist, i.e., miscibility gaps occur, which disappear at temperatures higher than the temperature of the
i/ transition. The miscibility gaps are reversible with temperature. The composition of the intercalated bilayers has been studied by HPLC of the excess alkanol mixture separated from the beidellite complexes after the equilibrium has been reached. There is preferential adsorption of one of two alkanols from the mixture, which is in agreement with the observed miscibility gaps. The space filling problem as well as the structure of the three bilayer phases observed have been discussed. 相似文献
990.
A non-empirical molecular orbital method, particularly suitable for calculations on cage-like molecules, is described. The method uses as basis functions the set of free-electron functions which are the solutions of Schrödinger's equation for an electron confined between two concentric, spherical potential energy barriers. Application of the theory to the SCF calculation of the energies of the delocalized electrons in benzene and tetrasulphur tetranitride shows that the model is capable of interpreting the properties of such systems. However, it does highlight a difficulty in the calculation of excited state energies with one-centre models which appears to be largely unrecognized.Extension of the method to a consideration of all the valence electrons, using P4 as an example, reveals problems the origin of which is an inadequate treatment of the core electrons. It is suggested that these problems may best be dealt with by use of a suitable pseudo potential. 相似文献