苄基紫精在金、铂电极上的伏安特性

The Voltammetric Behavior of Benzyl Viologen Bication on Gold and Platinum Electrodes

用循环伏安法研究了磷酸盐缓冲溶液（ｐＨ６．８）中苄基紫精（ＢＶ２＋）在金、铂电极上的伏安特性．考察了电位扫描下限（ＥＬ）、扫描速度（ｖ）、ＢＶ２＋浓度等因素对ＢＶ２＋电极过程的影响．在－０．４～０．９Ｖ（ｖｓ．ＳＣＥ）电位区，ＢＶ２＋的还原表现为两个阴极峰．当ＥＬ正于第二个还原峰电位时表现为可逆的ＢＶ（２＋／＋）氧化还原过程．当ＥＬ负于时，生成完全还原产物一中性紫精ＢＶ°，其氧化过程强烈依赖于ｖ和紫精浓度．在低浓度下，当高扫描速度时可观察到ＢＶ的可逆氧化；在高浓度下，即使扫描速度很高仍表现为不可逆的氧化过程．伏安特性中的异常现象用电荷转移络合物的形成予以解释．

The voltammetric behavior of benzyl viologen bication (BV￣(2+)) in phosphate buffer (pH6. 8) on gold and platinum electrodes has been studied. The effects of negative limit of potential scanning (E_L),the scan rate(u) and the concentration of BV￣(2+)(C_(BV￣(2+)))were investigated. When E_L>E￣Ⅱ_(pc),the second reduction peak potential of BV￣(2+), only redox of BV￣(2+/+) was observed, which was a diffusion-controlled reversible process. In the case of E_L<E￣Ⅱ_(pc) the oxidation of the completely reduced products,the neutral BV°, strongly depended on v and C_(BV￣(2+)). When C_(BV￣(2+)) was low the oxidation of BV° to BV￣+ was reversible at high scan rates, whereas no reversible oxidation of BV°was observed when C_(BV￣(2+)) was high. These results were discussed on the assumption of the formation of charge transfer complex (BVBV)￣ +.