Schiff碱基过渡金属镍络合物的电化学聚合:阳极电聚合中扫描速率的影响

摘要

Anodic electrochemical polymerization of N,N'-ethylenbis (salicylideneaminato) nickel(II) ([Ni(salen)])in tetrabutylammonium perchlorate (TBAP)/acetonitrile (AN) was investigated by the linear sweep potential method.The sweep rate ranged from 5 to 150 mV" s-1.The effect of sweep rate on the growth of poly[Ni(salen)] was studied by Coulomb analysis.The morphologies of poly[Ni(salen)] were characterized by field emission scanning electron microscopy (FESEM).The relationship between the growth rate of poly[Ni(salen)] (dF/dm) and the sweep rate (v) fits the exponential degradation equation.The content of the redox center for poly[Ni(salen)],grown at sweep rate Of 20 mV·s-a,reaches a maximum and then decreases as the sweep rate increases because monomer diffusion restricts therngrowth of poly[Ni(salen)].We studied the effect of polymerization sweep rate on the kinetics of the as-grown poly[Ni(salen)] by cyclic voltammetry.The charge diffusion coefficient (D) of poly[Ni(salen)] grown at a sweep rate of 20mV·s-1was found to be the highest.%采用线性电位扫描法制备了水杨醛-Schiff碱基过渡金属镍络合物的聚合物poly[Ni(salen)],扫描速率为5-150 mV·s-1.采用场发射显微镜观察了聚合物poly[Ni(salen)]的表面形貌.研究了电聚合中扫描速率对聚合物生长的影响,电聚合速率(dг/dm)与扫描速率(v)呈指数衰退关系,通过库仑电量分析指出电聚合扫描速率在20mV·s-1时聚合产物中含有最多的氧化还原活性点.扫描速率提高时单体的扩散步骤限制了聚合物的生长,所以氧化还原活性点总量随着扫描速率的提高而开始下降.利用循环伏安法分析了聚合物poly[Ni(salen)]的扩散动力学,结果表明在20 mV·s-1时制备的聚合物具有较大的电荷扩散系数.