以邻苯二甲酸单甲酯(mMP)为配体合成了一个新的双核铜配位化合物【Cu2(mMP)2(H2O)2】2·2H2O(1),并通过元素分析、红外光谱和X射线单晶衍射等方法对化合物晶体结构进行了表征.化合物1通过四羧酸桥联的方式形成了桨轮状双金属笼结构.每个Cu(Ⅱ)离子采用四方单锥的五配位构型,其中四个氧原子来自于四个不同的邻苯二甲酸单甲酯配体,轴向位置上的氧原子则来自于水分子.配位水分子和溶剂水分子与配体中未配位的氧原子形成了分子间氢键,并进一步形成三维网络结构.磁性数据显示双核铜内为强的反铁磁交换作用,磁耦合作用常数2J=-324cm^-1.通过与相关双核铜化合物的对比,详细分析了化合物的磁构关联并讨论了羧酸类双核铜中强反铁磁性作用的结构因素.研究表明,影响羧酸类双核铜强反铁磁性作用的主要结构因素是配体中桥联双核铜的O—C—O部分的电子结构.
We prepared and obtained a novel dinuclear copper(ll) coordination complex 【Cu2(mMP)2(H2O)2】2·2H2O(1) using mono-methyl phthalate as a ligand (roMP is a mono-methyl phthalate or 1,2- benzenedicarboxylate monomethyl ester). The crystal structure of complex 1 was characterized by elemental analysis, IR spectroscopy, and X-ray analysis. This tetra-carboxylato-bridged dinuclear complex adopts a dimeric paddle-wheel cage structure and the coordination configuration around each copper(Ⅱ) cation is square-pyramidal with four oxygen atoms of the carboxylate groups from four different mono- methyl phthalate ligands and one oxygen atom of water at the apical position. Intermolecular hydrogen bonds are found between the hydrogen atoms of the coordinated or uncoordinated water and the oxygen atoms of the carboxyl from the adjacent molecules and it forms a three-dimensional (3D) network structure. The magnetic data for complex 1 indicate a strong intramolecular antiferromagnetic interaction between the two paramagnetic metal ions with a magnetic coupling constant of 2J=-324 cm-1. In this paper, we analyzed the magnetostructural correlation of complex 1 in detail and discuss the main factor that determines the strong antiferromagnetic interaction in dimeric copper(ll) carboxylates. Compared with the structure and the magnetic property of other related complexes, the main factor that determines thestrong antiferromagnetic interaction in the dimeric copper(ll) carboxylate is an electronic structure of the bridging O--C--O moiety.