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合成并表征了3个含Cu2X2结构单元的双核Cu髣配合物[Cu2(μ-X)2(deebq)2](其中deebq=2,2′-联喹啉-4,4′-二甲酸乙酯;X=Cl(1),Br(2)or I(3))。化合物1~3同构,其晶体属三斜晶系,空间群为P1,具有相似的晶胞参数和晶体堆积结构。Cu2X2双核单元具有反演中心对称性,每个Cu+与deebq配体中2个N原子、2个μ2桥联的卤素X-阴离子配位,形成扭曲的四面体配位环境。通过deebq配体中苯环间π…π堆积,相邻双核分子形成超分子一维链,超分子链间存在弱范德瓦尔斯引力。在二氯甲烷溶液中,3个化合物都存在1个宽而不对称的电荷迁移吸收带(500~630 nm区域),其强度和位置不受桥联X-配体影响。因此,电荷迁移带归属为由Cu+中心到deebq配体的电荷转移。在二氯甲烷溶液中,3个化合物发射强荧光,发射带中心波长位于400 nm处,该发射带归属为deebq配体内的π-π*电子跃迁。在固体以及二氯甲烷溶液中,都没观察到从金属中心到配体的MLCT发射带。
Three Cu2X2 binuclear Cu pseudo-complexes [Cu2 (μ-X) 2 (deebq) 2] were synthesized and characterized (where deebq = 2,2’-biquinoline-4,4’-dicarboxylic acid B Ester; X = Cl (1), Br (2) or I (3)). Compounds 1 to 3 are isomorphic and their crystals are triclinic with space group P1, with similar cell parameters and crystal packing structure. Cu2X2 binuclear units have inversion center symmetry. Each Cu + coordinates with two N atoms in the deebq ligand and two μ2 bridged halogen X-anions to form a distorted tetrahedral coordination environment. Through deebq ligand benzene ring π ... π stacking, adjacent to the formation of two-core supramolecular one-dimensional chain, Supramolecular chains exist weak van der Waals attraction. In dichloromethane solution, there is one broad and asymmetric charge-transfer absorption band (500 ~ 630 nm) in all three compounds, whose intensity and position are not affected by bridging X-ligand. Therefore, the charge transfer band belongs to the charge transfer from the Cu + center to the deebq ligand. In dichloromethane solution, three compounds emit strong fluorescence with emission centered at 400 nm, which belongs to π-π * electron transition in deebq ligands. No MLCT emission bands from the metal center to the ligand were observed in the solid and in the dichloromethane solution.