混合配体构筑的配位聚合物的合成、结构与荧光性质

Syntheses, Structures and Luminescence Properties of Coordination Polymers in Mixed-Ligand System

在溶剂热条件下,利用Cd(Ⅱ)、Co(Ⅱ)在混配体体系下合成出3个结构新颖的配位聚合物[Cd_3(pic)_4(H_2bmimb)]n(1),[Co_3(pic)4(H_2bmimb)]n(2)和[Cd_2(1,2-mbix)(pic)_2(H_2O)_2]_n(3)(pic=5-苯基间苯二甲酸;H_2bmimb=1,4-二((2-甲基咪唑)亚甲基)苯;1,2-mbix=1,2-二((2-甲基咪唑)亚甲基)苯),并通过单晶X射线衍射、红外光谱、热重分析、元素分析、粉末X射线衍射和荧光光谱等对配合物进行了表征。配合物1和2中金属离子Cd^(2+)、Co^(2+)均与pic配体形成了三维阴离子骨架,双质子化的双咪唑配体位于骨架中平衡骨架电荷。配合物3中,Cd^(2+)金属中心与pic、1,2-mbix配体配位形成一维链,链与链之间通过苯环间的π…π堆积形成二维层,进而通过氢键形成三维超分子结构。配合物1和3表现出良好的荧光性质。

Three novel coordination polymers, formulated as [Cd3（pic）4（H2bmimb）]n （1）, [Co3（pic）4（H2bmimb）]n （2）, [Cd2（1,2-mbix）（pic）2（H2O）2]n （3） （H2bmimb=1,4-bis（（2-methyl-lH-imidazol-l-yl）methyl）benzene, 1,2-mbix=1,2-bis （（2-methyl-lH-imidazol-l-yl）methyl）benzene, pic=5-phenylisophthalic acid）, were synthesized by self-assembly of mixed ligands with Cd（Ⅱ） and Co（I） under solvothermal conditions and characterized by means of single-crystal X-ray diffraction, X-ray powder diffraction, infrared spectra, thermogravimetric analysis and fluorescence spectra. Single-crystal X-ray diffraction analysis revealed that complexes 1 and 2 possess 3D anionic frameworks, in which the protonated bis-imidazole ligands balance the charge of the frameworks. In complex 3, the Cd2＋ ions are linked by pic and 1,2-mbix ligands to generate a 1D chain structure. The adjacent chains are held together to form a 2D layer via π...π stacking and then a 3D supramolecular framework through hydrogen-bonding interactions. In addition, luminescence properties of complexes 1 and 3 in the solid state were characterized.