Yi Xiu-Guang, Chen Wen-Tong, Huang Jian-Gen, Zhang Ding-Wa, Wang Yin-Feng
Acta Chim Slov. 2017 Dec;64(4):1042-1047. doi: 10.17344/acsi.2017.3838.
A novel cadmium complex with mixed ligands [Cd(2,2'-biim)(4,4'-bipy)(H2O)(ClO4)] (ClO4)n (1) (2,2'-biim = 2,2'-biimidazole; 4,4'-bipy = 4,4'-bipyridine) has been synthesized through hydrothermal reaction and its crystal structure was determined by single-crystal X-ray diffraction technique. Single-crystal X-ray diffraction analyses revealed that complex 1 crystallizes in the space group Pna21 of the orthorhombic system and exhibits a one-dimensional zigzag chain structure consisting of [Cd(2,2'-biim)(4,4'-bipy)(H2O)(ClO4)]n n+ cationic chains and isolated ClO4 - anions. Powder photoluminescent characterization reveals that complex 1 has an emission in the green region of the spectrum. Time-dependent density functional theory (TDDFT) calculation showed that the nature of the photoluminescence of complex 1 is originated from the ligand-to-ligand charge transfer (LLCT; from the HOMO of the perchlorate anions to the LUMO of the 4,4'-bipy ligand). A wide optical band gap of 3.25 eV was found by the solid-state UV/vis diffuse reflectance spectrum.
通过水热反应合成了一种具有混合配体的新型镉配合物Cd(2,2'-联咪唑)(4,4'-联吡啶)(H₂O)(ClO₄)ₙ (1)（2,2'-联咪唑 = 2,2'-联咪唑；4,4'-联吡啶 = 4,4'-联吡啶），并通过单晶X射线衍射技术确定了其晶体结构。单晶X射线衍射分析表明，配合物1结晶于正交晶系的Pna21空间群，呈现出由[Cd(2,2'-联咪唑)(4,4'-联吡啶)(H₂O)(ClO₄)]ₙ⁺阳离子链和孤立的ClO₄⁻阴离子组成的一维锯齿链结构。粉末光致发光表征表明，配合物1在光谱的绿色区域有发射。含时密度泛函理论(TDDFT)计算表明，配合物1的光致发光性质源于配体到配体的电荷转移(LLCT；从高氯酸根阴离子的HOMO到4,4'-联吡啶配体的LUMO)。通过固态紫外/可见漫反射光谱发现其光学带隙为3.25 eV。
