双羧酸功能化苯并咪唑内鎓盐金属配合物的合成、晶体结构及热学性质研究

Synthesis,crystal structure and thermal properties of metal complex based on biscarboxylic-functionalized benzimidazole carboxylate

以2-乙基苯并咪唑为原料,与丙烯酸甲酯经过N原子的麦克加成反应得到了酯基功能化的苯并咪唑衍生物,后者发生N的季铵化和酯的酸性水解两步反应得到目标配体(N-羧乙基-N′-羧甲基-2-乙基苯并咪唑内鎓盐).然后,在水相中快速、方便地合成了一种双羧酸功能化苯并咪唑内鎓盐金属配合物[K(L1)(H2O)](L1=N-羧乙基-N′-羧甲基-2-乙基苯并咪唑内鎓盐).用元素分析、红外光谱、热重分析对其进行了表征,单晶X射线衍射测定了配合物的晶体结构.结果表明,此配合物属于正交晶系,Pbca空间群,晶胞参数a=1.715 0(9)nm,b=1.000 5(6)nm,c=1.822 3(10)nm,V=3.127(3)nm3,Z=8,F(000)=1 392.配合物通过分子间氢键和π-π相互作用自组装成了三维网状结构.

2-ethylbenzimidazole reacts with methyl acrylate to give the ester-functionalized benzimidazole derivative by the aza-Michael addition,the latter suffers two raction processes containing quaternarization and hydrolysis to give the title ligand（N-carboxyethyl-N′-carboxymethyl-2-ethylbenzimidazole）,then asupramolecular metal complex[K（L1）（H2O）]（L1=biscarboxylic-functionalized benzimidazole carboxylate） have been synthesized in water solution and characterized by elemental analysis,IR and TG.The molecular structures is determined by single crystal X-ray diffraction.The results show that the complex crystallizes in the orthorhombic system with space group Pbca,a=1.715 0（9） nm,b=1.000 5（6） nm,c=1.822 3（10） nm,V=3.127（3） nm3,Z=8,F（000）=1 392.The complex self-assembled shows 3-dimensional net structures supported by H-bonds and π-π interactions.