Abstract A new binuclear Cd(II) complex, [Cd2(H2tmidc)4(H2O)2]·6H2O (1) based on 2-(1H-tetrazol-1-methyl)-1H-imidazole-4,5-dicarboxylic acid (H3tmidc) has been synthesized and structurally characterized. The single-crystal X-ray diffraction analysis has revealed that there are two crystallographically distinct H2tmidc– anions in complex 1, one of which is coordinated to Cd(II) ion in a terminal fashion, while the other acts as a bis-connector linking two Cd(II) cations to form the dinuclear structure. The dimeric units are stabilized by intra-molecular O–H···O hydrogen bonds and π-π stacking interactions and are further connected into a three-dimensional supramolecular architecture through inter-molecular hydrogen bonds and π-π stacking interactions. The interactions of complex 1 with bovine serum albumin (BSA) were analyzed by fluorescence measurements under physiological conditions. The results have indicated that the fluorescence intensity of BSA was decreased considerably upon the addition of complex 1 through a static quenching mechanism. The synchronous fluorescence spectrum suggested that the interaction of complex 1 with BSA affects the conformations of tryptophan and tyrosine residues and thereby has an influence on the conformation of BSA.

中文翻译：

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基于 2-(1H-四唑-1-甲基)-1H-咪唑-4,5-二羧酸的新型双核 Cd(II) 复合物的合成、分子结构和 BSA 结合特性

摘要 基于 2-(1H-四唑-1-甲基)-1H-咪唑-4,5-二羧酸的新型双核 Cd(II) 配合物 [Cd2(H2tmidc)4(H2O)2]·6H2O (1) (H3tmidc) 已被合成和结构表征。单晶 X 射线衍射分析表明，配合物 1 中有两个晶体学上不同的 H2tmidc– 阴离子，其中一个以末端方式与 Cd(II) 离子配位，而另一个作为双连接器连接两个 Cd(II) 阳离子形成双核结构。二聚单元通过分子内O-H···O氢键和π-π堆积相互作用稳定，并通过分子间氢键和π-π堆积相互作用进一步连接成三维超分子结构。在生理条件下通过荧光测量分析复合物 1 与牛血清白蛋白 (BSA) 的相互作用。结果表明，通过静态猝灭机制，加入配合物 1 后 BSA 的荧光强度显着降低。同步荧光光谱表明复合物1与BSA的相互作用影响色氨酸和酪氨酸残基的构象，从而对BSA的构象产生影响。