【摘要】 在溶剂热条件下,将一个V-型双咪唑配体1,1′-(5-甲基-1,3-亚苯基)二(1H-咪唑)(Bim)与其它V-型辅助配体(具有不同的对称性和功能基团的芳香羧酸)一起与金属盐Zn SO4·6H2O进行反应,分别得到2个新的配位聚合物{[Zn(Bim)(Bra)2]·CH3OH}n(1)和{[Zn(Bim)(Mpa)]·H2O}n(2)(Bra-=5-溴烟酸根,Mpa2-=5-甲基间苯二甲酸根)。采用红外光谱、元素分析、X射线粉末衍射、X射线单晶衍射和热重分析对配合物进行了表征。配合物1是由配体Bim桥联形成的一维链状结构并进一步通过链间的π…π、C-H…π和Br…π作用堆积成一个三维超分子。在2中,Zn(Ⅱ)离子通过Mpa2-桥联形成左手和右手螺旋链,这些具有不同手性的螺旋链进一步通过Bim联接形成具有(4,4)拓扑结构的内消旋的二维层。相邻的二维层之间的交错对插、层间配体分子Bim的咪唑环和苯环的双重π…π作用最终形成了三维超分子。固态荧光测试结果表明:在室温条件下,配体Bim和配合物1~2均出现了有趣的多重发射峰,而且在配合物1中四配位的Zn(Ⅱ)离子中心能显著地敏化配体Bim的高强度发射峰。更多还原

【Abstract】 A V-shaped bis-imidazole ligand 1,1′-(5-methyl-1,3-phenylene)-bis(1H-imidazole)(Bim) in combination with auxiliary V-shaped ligands aromatic carboxylic acids of different symmetry and functional groups was selected to react with Zn SO4·6H2O under solvothermal condition, and two new coordination polymers, {[Zn(Bim)(Bra)2]·CH3OH}n(1) and {[Zn(Bim)(Mpa)]·H2O}n(2), were obtained(Bra-=5-bromonicotinate and Mpa2-=5-methylisophthalate). The two compounds were characterized by IR spectra, element analysis, powder X-ray diffraction, single-crystal X-ray diffraction, and thermogravimetric analysis. Compound 1 features Bim-bridged one-dimensional chain structures which stack up through interchain π … π, C-H … π and Br … π interactions to form a three-dimensional supramolecule. In 2, zinc (Ⅱ) ions are bridged by Mpa2-ligands to form left- and righthanded helical chains which are further linked into(4,4) meso layers through Bim molecules. Finally, a 3D supramolecular framework forms through the interdigitation and double π … π interactions between the imidazole and phenyl of Bim molecules in adjacent layers. Solid state fluorescence measurements confirm that at room temperature both free ligand Bim and complexes 1 ~2 displays interesting multiple emissions, and the fourcoordinated Zn (Ⅱ) center in 1 can notably sensitize the high-energy emission of Bim.更多还原