一维单链4-吡啶甲醛缩氨基硫脲合锌(Ⅱ)配位聚合物[Zn(HL)(CH3COO)2·H2O]n的合成、晶体结构及配体的新颖配位模式

Synthesis and Crystal Structure of One-dimensional Single-chain Zn(Ⅱ) Complex Containing Pyridine-4-carbaldehyde Thiosemicarbazone and Novel Coordination Mode of Ligand

4吡-啶甲醛缩氨基硫脲(HL)与醋酸锌反应得到了标题配位聚合物[Zn(HL)(CH3COO)2.H2O]n(1)。采用元素分析、红外光谱、紫外光谱和单晶X射线衍射测试技术对其结构进行了表征。单晶X射线衍射分析表明,在标题配位聚合物1中,Zn2+离子与1个配体HL中的吡啶环上的氮原子,另外1个配体HL中的硫原子以及2个醋酸根上的氧原子配位,构成了锌离子的畸变四面体构型;每个HL分别以吡啶环上的氮原子和硫原子以头对尾的方式与2个锌离子配位,从而将锌离子依次桥联,形成了类螺旋形链结构,链间通过氢键和π-π相互作用形成三维网络结构。HL潜在的NNS三齿配位点中亚胺N没有配位,吡啶N和S采取头对尾的NS配位模式是比较新颖的。

The title complex was synthesized from the reaction of pyridine-4-carbaldehyde thiosemicarbazone with zinc acetate and characterized by elemental analysis, IR, UV and X-ray crystal diffraction. The X-ray diffraction revealed that title complex 1 contains one four-coordinated zinc ion connected by two thiosemicarbazone ligands via the pyridyl nitrogen atom of one thiosemicarbazone ligand, the sulfur atom, two oxygen atoms of two acetate anions coordinating through the other thiosemicarbazone ligand, forming a distorted tetrahedron of Zn（ Ⅱ ） ion. Each ligand adopting the head-to-end coordination mode coordinates to two zinc ion via the pyridine nitrogen and sulphur atoms, respectively. Thus zinc ions are bridge-linked to form an pseudo-helical chain framework. Between the chains, three-dimensional network framework is formed by hydrogen bonding and π-π interactions. It is novel that the pyridine nitrogen atom and sulphur atom of a potential NNS tridentate thiosemicarbazone without using its imine nitrogen adopt the head-to-end NS coordination mode.