Spectroelectrochemical approaches to heterogeneous electron transfer reactions at the polarised water|1,2-dichloroethane interfaces

摘要

Heterogeneous electron transfer (ET) reactions at the polarised water|1,2-dichloroethane (DCE) interface are studied by in situ UV-Visible spectroscopy in total internal reflection mode. The reduction of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and the oxidation of 1,1'-dimethylferrocene (DMFc) by the hexacyanoferrate redox couple are considered. The generation of products in the organic phase is monitored spectroscopically and correlated to the simultaneous current response. Both systems exhibit a good correlation between optical and electrochemical responses, highlighting the ideal behaviour of these redox couples for electron transfer studies at liquid|liquid interfaces.The kinetics of ET between hexacyanoferrate and TCNQ is analysed also by chronoabsorptometry and potential modulated reflectance spectroscopy. The potential dependence of the ET rate constant is discussed within the framework of the ET models for ITIES.