2-氨基吡啶类双核铜(Ⅱ)配合物的合成、晶体结构及性质

Syntheses, Crystal Structures, and Properties of Binuclear Copper(Ⅱ) Complexes Derived from 2-Aminopyridines

分别以3-甲基-2-氨基吡啶(L_(1))、5-溴-2-氨基吡啶(L_(2))为配体,采用溶液法合成了2个新的双核铜配合物:[Cu_(2)(CH_(3)COO)_(4)(L_(1))_(2)](1)和[Cu_(2)(CH_(3)COO)_(4)(L_(2))_(2)](2),并利用熔点、红外光谱、紫外可见光谱、荧光光谱、高分辨质谱和X射线单晶衍射等手段对其进行表征。1属于正交晶系Pbca空间群;2属于单斜晶系P2_(1)/n空间群。每个配合物含有2个铜中心离子、4个醋酸根离子和2个配体(L_(1)或L_(2))分子;每个醋酸根都起到桥联作用,分别与2个Cu^(2+)配位,形成笼状结构;每个Cu^(2+)均为五配位变形四方锥构型。1和2对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌显示出良好抑制作用;对DPPH·具有良好清除效果;均表现出准可逆氧化还原的电化学特性。

3-Methyl-2-aminopyridine(L_(1)) and 5-bromo-2-aminopyridine(L_(2)) were used as ligands respectively,and two novel binuclear copper(Ⅱ) complexes,[Cu_(2)(CH_(3)COO)_(4)(L_(1))_(2)](1) and [Cu_(2)(CH_(3)COO)_(4)(L_(2))_(2)](2),have been synthesized by the reaction of the above-mentioned ligands with anhydrous cupric acetate in ethanol solution.The two copper(Ⅱ) complexes were characterized by the methods of melting point,FT-IR,UV-Vis,fluorescence spectra,and HRMS.The crystal structures of 1 and 2 were analyzed by single-crystal X-ray diffraction,which indicates that 1 crystallizes in the orthorhombic system with Pbca space group,while 2 crystallizes in the monoclinic system with P2_(1)/n space group.Each of the two binuclear Cu(Ⅱ) complexes contains two copper center cations,four acetate ions,and two L_(1) or L_(2) ligands.Each acetate acts as a bridging ligand and coordinates to two Cu(Ⅱ) cations forming a cagelike structure.Each Cu(Ⅱ) cation in complexes 1 or 2 is pentacoordinate to one N atom in one pyridine ring and four O atoms in four acetate ions,and the geometries around Cu(Ⅱ) in 1 or 2 are distorted square pyramid.The antibacterial activities of 1 and 2 were investigated by the agar diffusion method,and the result indicated that 1 and 2 had good antibacterial inhibiting effects against Staphylococcus aureus,Bacillus subtilis,and Escherichia coli.And their antioxidant activities were valued using the 2,2-diphenyl-1-picrylhydrazyl(DPPH·) method,which showed that both of them possessed good scavenging capability on DPPH·.Moreover,the electrochemical properties of 1 and 2 were studied by the cyclic voltammetry method, and the results indicate that 1 and 2 showed quasi-reversible redox pro-cesses. CCDC: 2123588,1;2123589,2.