Cd(Ⅱ)-btec配聚物的合成、结构及光电性能

Syntheses,Structures and Surface Photo-electric Properties of Cd(Ⅱ)-btec Coordination Polymers

采用水热法合成了Cd(Ⅱ)配聚物[Cd3Na2(btec)2(H2O)2]n(1)和{[Cd3Na2(btec)2(H2O)2].4H2O}n(2)(H4btec=1,2,4,5-苯四甲酸).单晶结构解析结果表明,配聚物1和2的不对称单元中均包含2种晶体学不等效的Cd(Ⅱ)离子,分别为六配位和八配位,均通过btec4-基团桥连成具有3D无限结构的配聚物.二者区别在于:2个配聚物中Na(Ⅰ)离子的配位环境不同,且配聚物2中存在游离水分子.表面光伏技术研究结果表明,2个配聚物在300～500 nm范围内呈现出明显的光伏响应,表明它们具有一定的光-电转换能力.对配聚物的表面光电压谱(SPS)与紫外-可见吸收光谱(UV-Vis)进行了关联,并对配聚物进行了X射线衍射(XRD)和热重(TG)分析.

Two Cd（Ⅱ） coordination polymers [Cd3Na2 （btec）2（H2O）2]n（1） and {[Cd3Na2（btec）2·（H2O）2]·4H2O}n（2）（H4btec=1,2,4,5-benzenetetracarboxylic acid） were synthesized by hydrothermal method. The structures were determined by single crystal X-ray diffraction. Structural analyses show that the asymmetric units of polymers 1 and 2 contain two crystallographically unique Cd（Ⅱ） ions with six- and eight-coordinate, respectively, and they possess 3D structures bridged by btec4- groups. The structure differences between them are that the coordination environment around Na（Ⅰ） ions is different and polymer 2 has lattice water molecules. The photo-electric properties of the two polymers were investigated by surface photovoltage spectroscopy（SPS）. The results of SPS show that the two polymers exhibit obvious photovoltage responses in the range of 300-500 nm, which indicates that they all possess certain photo-electric conversion properties. The SPS and UV-Vis spectra of the polymers were interrelated, and XRD patterns and TG curves of the two polymers were measured and analyzed.