基于混合配体构筑的链状配位聚合物的合成与结构表证

Synthesis and characterization of chain coordination polymers constructed from mixed ligands

以1,2,5-噻二唑-3,4-二酸(H_2tdzdc)为主配体,具有螯合配位能力的2,2′-联吡啶为辅助配体,通过水热法合成了2个一维链状配合物,并对其进行了元素分析、红外光谱及单晶衍射结构解析.单晶结构解析表明:配合物[Co(tdzdc)(bpy)(H_2O)]n(1)和配合物[Cd(tdzdc)(bpy)(H_2O)]n(2)均为一维链状结构,前者为折线型,后者是直线型.配合物1属于正交晶系Pna21空间群,配合物2结晶于三斜晶系P-1空间群.研究发现配位过程中先是金属离子与H2tdzdc配体形成了一维链,辅助配体2,2′-联吡啶再以螯合的形式与中心离子相结合,从而阻断了一维链进一步向多个方向的连接.辅助配体2,2′-联吡啶以"卡角"的形式参与配位,阻断配合物形成高维结构,这在调控结构上有一定的意义.

Two new CoⅡ/CdⅡcoordination polymers,named [Co（tdzdc）（bpy）（H2O）]n（1）and[Cd（tdzdc）（bpy）（H2O）]n（2）have been synthesized by hydrothermal reactions of M（OAc）2,1,2,5-thiadiazole-3,4-dicarboxylic acid（H2tdzdc）and chelation ligand 2,2′-bipyridine（2,2′-bipy）.They exhibit one-dimensional Zigzag and linear chain structures,respectively.The structures of coordination polymers have been determined by single-crystal X-ray diffraction analyses,and further characterized by elemental analyses,IR and powder X-ray diffraction.The difference between coordination polymers 1 and 2 in their crystal structures reveals diversified coordination modes of H2 tdzdc ligand toward different metal ions.The chelation ligand,2,2′-bipy ligand has sterically hindered effect and can change the structure of target compounds,which is of certain significance in regulating the structure.