配合物[Fe(ntb)Cl_2]Cl·THF·H_2O的合成、电化学和多酚氧化酶性质研究

Synthesis,electrochemistry and polyphenol oxidase activities studies of [Fe(ntb)Cl_2]Cl·THF·H_2O

合成了三(2-苯并咪唑甲基)胺(ntb)为配体的单核铁(Ⅲ)配合物[Fe(ntb)Cl2]Cl.THF.H2O,对配合物进行了IR、UV-vis和元素分析等表征.通过单晶X-射线衍射确定了其晶体结构,配合物阳离子含有一个中心金属Fe(Ⅲ)离子,与一个烷基胺氮、三个苯并咪唑氮和两个氯离子配位,形成畸变八面体构型.配合物分子和外界阴离子以及溶剂分子之间通过氢键作用形成三维网络结构.用循环伏安法研究了配合物的电化学性质,在0.8～-0.8V(vs.SCE)电位扫描范围内,配合物呈准可逆的氧化还原行为.在pH 8.2和40℃的条件下,以邻苯二酚为底物,研究了配合物的拟多酚氧化酶活性,结果表明,配合物催化邻苯二酚氧化呈准一级动力学反应,其速率常数为0.32min-1.

The mononuclear Fe（M） complex, [Fe（ntb）Cl2]Cl · THF · H2O has been synthesized in tetrahydrofuran solutions and characterized by element analysis, IR, UV and single crystal X-ray diffraction method. In the complex, the Fe（III） atom is coordinated by four N atoms of the polybenzimidazole ligand ntb and two Cl ions in a distorted octahedral environment. It is further linked through hydrogen bonds interactions by one Cl ion, the uncoordinated water molecule and the tetrahydrofuran solvent molecule to form a three-dimensional supramolecular network structure. Within the scan range of 0.8 to --0.8V （vs. SCE）, The electrochemical properties of complex was investigated by the cyclic voltammogram. The CV of complex demonstrated that there was a pair of quasi-reversible cathode and anodic peaks. Polyphenol oxidase activity toward catechol has been studied spectroscopically. Pseudo-first-order kinetic is fitted with the experimental data. The velocity constant of the complex toward catechol is 0.32 min- 1 at pH 8.2 and 40℃. The result shows the complex has polyphenol oxidase activity.