Homogeneous "protonation" and heterogeneous "electron transfer" reactions pertaining to the second reduction process of some dinitro aromatics

Abstract

Electrochemical investigations were carried out on three dinitro benzene dianions ; 1,2 - 1,3 and 1,4 dinitro benzene dianions. These dian ions were found to be quite reactive. These compounds were studied by two different techniques , cyclic voltammetry and differential pulse cyclic vol tammetry. Homogeneous (protonation ) rate cdnstants for the protonation of dianions were calculated using Nicholson and Shain(22) equation. Heterogeneous (electron transfer) rate constants were cal¢ulated from Nicholson's(19) Russel's (21 ) methods. , Kochi's(20) and -k -k * Activation parameters, E a , 6H, 6G, 6S for homogeneous process were calculated, while heterogeneous process were calculated for these dinitro benzene dianions. Differential pulse voltammetry data for these dianions were analyzed and from the graphs of (E - E1 ) vs 1 n k f P ~ (from cyclic voltammetry data ) , slopes and intercepts of these plots were obtained.