刚性二咪唑配体组装金属有机大环与金属有机凝胶的结构与性质

用配体2?(4?吡啶基)?咪唑(4?PIM)和2?(4?(1?咪唑基)?苯基)?咪唑(IPI)分别与AgClO4和ZnCl2反应得到了配合物Ag(4?PIM)]ClO4(1)和Zn(IPI)]Cl2·H2O(2)。晶体结构分析表明配合物1与2分别具有M4L4和M2L2金属有机大环结构,且金属有机大环分子结构中存在较强的分子间作用力、芳环之间π?π作用和氢键作用。刚性配体IPI分别与AgNO3和Zn(NO3)2在甲醇、乙醇、二甲基亚砜、乙二醇、四氢呋喃、乙腈等有机溶剂中均能形成超分子凝胶;在乙醇溶剂中IPI与AgNO3、AgClO4、AgBF4、AgPF6、Ag(OSO2CF3)、Zn(NO3)2、Zn(BF4)2、Zn(ClO4)2、Co(NO3)2分别作用也能形成金属有机凝胶。配体IPI分子中咪唑环的1号位的N原子连接H原子,能分别与水分子或者溶剂分子之间形成氢键,可能是“锁”住溶剂分子形成凝胶的关键因素。扫描电镜图片显示配体IPI与AgNO3等银盐和Zn(NO3)2等锌盐在不同溶剂中能分别形成蓬松棉花状结构和疏松似面包状结构的金属有机超分子凝胶。

Crystal Structure and Properties of Metal-Organic Macrocycles and Metal-Organic Gels Based on Rigid Bis-imidazole Ligand

ComplexesAg(4?PIM)]ClO4(1)andZn(IPI)]Cl2·H2O(2)were synthesized by the reaction of ligand 2?(4?pyridinyl)?imidazole(4?PIM)and 2?(4?(1?imidazolylphenyl))?imidazole(IPI)with AgClO4 and ZnCl2,respectively.Xray crystallography analysis reveals that complexes 1 and 2 have metal?organic macrocyclic structure of M4L4 and M2L2 type,respectively.And there are stronger intermolecular forces,π?πstacking effect and hydrogen?bonding interactions in the crystal structures of complexes.Metal?organic gels were formed by using rigid ligand IPI to react with AgNO3 and Zn(NO3)2 in methanol,ethanol,dimethyl sulfoxide,ethylene glycol,tetrahydrofuran and acetonitrile,respectively.Supramolecular metal?organic gels were also self?assemblied through ligand IPI reacting with AgNO3,AgClO4,AgBF4,AgPF6,AgOSO2CF3,Zn(NO3)2,Zn(BF4)2,Zn(ClO4)2 and Co(NO3)2 in ethanol solvent,respectively.The hydrogen?bonding interactions between solvent molecules and N—H in the imidazole rings of ligand IPI may be the key factor to form gels.Scanning electron microscopy(SEM)images showed that metal?organic supramolecular gels based on silver salts or zinic salts had fluffy cotton?like and loose bread?like structure,respectively.CCDC:2017307,1;2017308,2.