山梨醇改性聚乙烯醇体系的氢键作用及对水状态的影响

采用二维相关红外光谱研究了水渗透进入聚乙烯醇(PVA)及其改性基体过程中, 体系的氢键作用及对水状态的影响; 通过差示扫描量热分析(DSC)研究了改性剂山梨醇(S)对改性PVA中水状态的影响. 实验结果表明, S能通过其羟基与水形成较强氢键, 从而显著改变体系中水的状态及其蒸发行为, 使体系自由水含量逐渐减少, 水的蒸发峰温度升高.     

基于含锌有机配位聚合物的微孔碳的合成及其电化学性能

报道了一种基于含锌(II)有机配位聚合物制备微孔碳的新方法. 通过锌离子和酒石酸之间的配位作用获得含锌有机配位化合物, 并通过氢键作用将其引入到间苯二酚/甲醛低聚物溶胶的开放网络结构中. 使含锌有机配位化合物和酚醛低聚物溶胶体系发生共聚反应得到酚醛和含锌有机配位共聚物, 在950℃下热处理分解以及锌蒸气蒸发后制得微孔碳. 微孔碳材料典型样品具有相对较大以及比较规则的微孔, 其比表面积可以达到1260 m²·g^-1, 孔体积为0.63 cm³·g^-1. 所得微孔碳作为超级电容器电极材料的等效串联电阻为0.46 Ω, 其循环伏安曲线展示出较好的矩形性. 恒流充放电分析结果表明, 当电流密度为1 A·g^-1时, 微孔碳电极的比电容为196 F·g^-1; 在10 A·g^-1的大电流密度下, 比电容仍然达到137 F·g^-1. 该电极具有优良的循环稳定性, 1000次循环后比电容保持率达到98%. 这一研究结果表明, 所得微孔碳在超级电容器电极材料方面具有重要的应用前景.     

Hydrothermal Syntheses and Crystal Structures of Zn(Ⅱ) and Co(Ⅱ) Complexes Constructed from 5-Methoxyisophthalic Acid and 1,10-Phenanthroline Ligands

Two new one-dimensional coordination polymers,[Zn(L)(phen)]n 1 and {[Co2(L)2(phen)2]·2H2O}n 2(H2L=5-methoxyisophthalic acid,phen=1,10-phenanthroline),have been obtained by hydrothermal conditions.According to their single-crystal X-ray diffraction analyses,complex 1 crystallizes in the monoclinic system,space group P2/c with a=8.9195(11),b=12.3620(15),c=17.0211(18),β=106.690(5)o,V=1797.7(4)3,the final R=0.0298 and wR=0.0715 for 3351 independent reflections with Rint=0.0353.Complex 2 crystallizes in the monoclinic system,space group C2/c with a=24.981(4),b=11.1204(19),c=18.125(3),β=132.5620(10)o,V=3708.5(11)3,the final R=0.0349 and wR=0.0914 for 3424 independent reflections with Rint=0.0214.Both 1 and 2 show L-bridged one-dimensional chain.1 and 2 are further assembled by π-π and hydrogen bonding interactions into 2-D layer structures,and they also display 3-D supramolecular frameworks through their other hydrogen bonds.Zn(Ⅱ) ion is five-coordinated with a distorted trigonal bipyramidal coordination geometry,while Co(Ⅱ) ion is six-coordinated and resides in a distorted octahedral coordination geometry.Additionally,complex 1 shows fluorescence in the solid state at room temperature.     

Syntheses, Crystal Structures and Characterization of Two New Cadmium（II） Arsonates

Two cadmium arsonate coordination polymers, Cd(HL1)2 (1, H2L1 = 4-aminophenylarsonatic acid) and Cd(H2L2)2·2H2O (2, H3L2 = 2-(4-arsonphenylamino)acetic acid), have been synthesized and characterized by IR and single-crystal X-ray diffraction. Crystal data for 1: triclinic, space group P1 with a = 5.7559(12), b = 7.0903(14), c = 8.9925(18), α = 89.04(3), β = 80.79(3), γ = 85.09(3)o, Dc = 2.496 g·cm-3, μ = 6.095 mm-1, F(000) = 260, Z = 1, the final R = 0.0574 and wR = 0.1376 for 1489 observed reflections with I > 2σ(I). And those for 2: monoclinic, space group P21/c with a = 4.7595(10), b = 9.925(2), c = 22.609(5), β = 91.81(3)°, Dc = 2.167 g·cm-3, μ = 4.168 mm-1, F(000) = 684, Z = 2, the final R = 0.0335 and wR = 0.0815 for 2340 observed reflections with I > 2σ(I). The structure of 1 shows a two-dimensional layer consisting of inorganic chains of {CdN2(AsO3)2} along the a axis linking with the phenyl groups. These layers are further linked through strong interlayer hydrogen bonding interaction to form a three-dimensional hydrogen bond supramolecular architecture. Compound 2 has inorganic chains of {CdO2(AsO3)2} similar to 1, which connect with four adjacent inorganic chains forming a three-dimensional framework.     

原位核磁共振技术考察L-缬氨酸导引下合成花状纳米结构聚苯胺形成机理的研究

利用~1H-NMR原位追踪在L-缬氨酸存在下合成花状纳米聚苯胺的形成过程中发现此结构的形成经历3个阶段:首先在苯胺与缬氨酸构成的类胶束结构内聚合成吩嗪类寡聚物;其次通过p-p重叠作用及胶束融合过程成为片状聚集体;最终通过与缬氨酸形成氢键组装成花瓣状纳米聚苯胺.通过改变反应条件,对比形成过程中核磁共振图谱及产物形貌的变化发现花状纳米聚苯胺的形成有如下特征:反应初期L-缬氨酸作为缓冲试剂可以避免苯胺的骤然质子化,有利于生成具有吩嗪结构的寡聚物;反应前苯胺单体与缬氨酸形成稳定的反应环境保证寡聚物始终在其内聚集生长,有效避免了外部环境的影响.     

Study on the Anion Recognition Properties of Synthesized Receptors （Ⅲ）： Convenient Synthesis and Anion Recognition Property of Bisthiosemicarbazone Derivative

A new series of bisthiosemicarbazone derivative receptors(1,2 and 3)have been synthesized by simple steps ingood yields.Their anion recognition properties were studied by UV-Vis and ~1H NMR spectroscopy.The resultshowed that the receptors 1,2 and 3 all had a better selectivity to F~-,CH_3COO~- and H_2PO_4~-,but no evidentbinding with Cl~-,Br~-,I~-,NO_3~- and HSO_4~-.Upon addition of the three anions to the receptors in DMSO,thesolution acquired a color change from colorless to dark yellow that can be observed by the naked-eyes,thus the re-ceptors can act as fluoride ion sensors even in the presence of other halide ions.The data showed that it was regularthat the three receptors had different binding ability with the three anions.For the same anion,the association con-stants followed the trend:receptor 1>3>2.The UV-Vis data indicates that a 1:1 stoichiometry complex isformed through hydrogen bonding interactions between compound 1,2 or 3 and anions.     

类晶加合物(M=Co,Cu, Ni)的晶体结构及分子间相互作用的理论研究

合成了3种化合物 [2-ClPyH]2CoCl4(1), [2-ClPyH]2NiCl4(2)和[2-ClPyH]2CuCl4(3), 单晶X射线衍射法晶体结构测定结果表明, 这3种化合物是同形加合物, 在它们的结构中, [2-ClPyH]+离子呈平面状, 而[MCl4]2-离子为变形的四面体. 晶体结构分析发现晶体中存在N—H…Cl和C—H…Cl氢键, 以及Cl…Cl分子间相互作用和π-π堆积作用. 对自由状态下独立的配位离子进行的几何构型优化, 以及三维周期性条件下几何结构优化的量子化学计算结果表明, 标题化合物中具有方向性和选择性的氢键决定延伸性结构的方向, 而相对较弱的卤素…卤素作用在最终晶体结构的确定中扮演很重要的角色.     

氢键在分子自组装中的花样

介绍氢键的基本花样类型。由氢键组装的复杂结构大都是由4种基本类型构成。对醇类、羧酸、酰胺、α-氨基酸分别研究,阐述了不同剩余集团对氢键花样的影响。简单介绍了氢键作用在超分子化学中的作用。