两个基于氢键构筑的超分子镁配合物的合成、 晶体结构及荧光性质

以5,6-苯并咪唑二酸(H₃bidc)为有机配体, 在水热条件下通过控制反应温度得到了2个镁配合物Mg(Hbidc)(H₂O)₄](1) 和 Mg(Hbidc)(H₂O)₅]·4H₂O(2). 通过单晶及粉末X 射线衍射、 红外光谱、 元素分析和热重分析对配合物进行了表征. 结果表明, 配合物1和2均为单核分子, 分别以不同的堆积方式通过氢键构筑成三维超分子结构. 值得注意的是, 配合物2的结构中捕获了由氢键连接的环状四聚体水簇(H₂O)₄. 配合物1和2的电荷布居分析结果与晶体结构的讨论一致. 此外, 固体荧光分析表明, 配合物1和2在室温下具有较强的蓝光发射.

Syntheses,Crystal Structures and Luminescent Properties of Two Magnesium(Ⅱ) Supramolecular Architectures Based on Hydrogen Bonds†

Two structurally diverse magnesium centered complexes with formula Mg(Hbidc)(H₂O)₄](1) and Mg(Hbidc)(H₂O)₅]·4H₂O(2), constructed from multidentate ligand 1H-benzimidazole-5,6-dicarboxylic acid(H₃bidc), were synthesized under hydrothermal conditions with identical reactants at different temperatures. The complexes were characterized by Fourier transform infrared(FTIR) spectroscopy, elemental analysis, thermogravimetric analysis(TGA), and powder and single-crystal X-ray diffraction(XRD) analyses. Complexes 1 and 2 both display neutral mononuclear structures, and their distinct crystal packing patterns are driven by strong intra- or inter-molecular hydrogen bonds. Interestingly, unprecedented hydrogen-bonded cyclic tetrameric water clusters(H₂O)₄ are observed in complex 2. In addition, luminescent studies show that the title compounds exhibit intense blue fluorescence emissions at room temperature in the solid state.