联咪唑镍、镉配合物的合成、晶体结构及其与DNA相互作用

分别通过水热法和室温挥发法合成了2,2'-联咪唑(H₂biim)镍、镉配合物([Ni(H₂biim)₃](phth)(phth,邻苯二甲酸根)(1)、[Cd(H₃biim)₂Cl₄](2)),并通过X射线单晶衍射、元素分析和红外等技术手段对它们进行了表征。 单晶X衍射结果表明,配合物1的配离子中心镍离子周围的配体以3个中性联咪唑分子形式分别进行二齿螯合配位,构成六配位的畸变八面体构型,邻苯二甲酸根离子在外界与配体形成丰富的氢键;而在配合物2中,两个联咪唑配体却以含有氢质子的阳离子H₃biim⁺形式与中心镉离子单齿配位,镉离子同时结合4个氯原子形成六配位配位环境。 通过紫外光谱、荧光光谱和黏度法测试结果表明配合物1和2分别与小牛胸腺DNA(ct-DNA)以经典插入和部分插入模式进行相互作用。

Synthesis,Crystal Structures and DNA Interaction of Nickel and Cadmium Complexes Involving Biimidazole

Two complexes {[Ni(H₂biim)₃](phth)}(H₂biim=2,2'-biimidazole, phth=phthalate)(1) and [Cd(H₃biim)₂Cl₄](2) were synthesized under hydrothermal and common solution conditions, and characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction analysis. Complex 1 consists of [Ni(H₂biim)₃]²⁺ cations hydrogen bonds with phthalate dianions. Each Ni atom coordinates six N atoms of three chelating biimidazole ligands in a pseudo-octahedral geometry. Complex 2 is a neutral compound. One N atom in H₂biim is protonated, forming a H₃biim⁺ cation. The central metal Cd is coordinated by two unidentate H₃biim⁺ ligands and four Cl atoms. The binding of the complexes with calf thymus DNA has been investigated by UV and fluorescence spectroscopy and viscosity measurement. All of the results indicate that the complexes 1 and 2 bind to DNA base pairs in intercalation and partial intercalation modes, respectively.