Abstrakt

Voltammetric studies of 5-substituted isatins

A.K.Gupta, R.S.Sindal

In the present study, the electrochemical behavior of isatin, a potent endogenous neurochemical regulator in brain and some of its more effective 5-substituted analogues in DMF has been investigated at glassy carbon electrode (GCE) using cyclic (CV) and differential pulse voltammetry (DPV) techniques in 0.1 M LiCl solution. All the chosen substituted isatins (Ia-Ih) were found to exhibit twowell-defined diffusion-controlled irreversible reduction waves. The number of electron transferred and the reduction products were identified using controlled potential electrolysis. Effect of scan rate and concentration of depolarizer on voltammetric response is also studied. An interesting correlation between half wave potential (E1/2) values of various substituents and Hammett substituent constant () has been interpreted. The kinetic parameter i.e. charge transfer coefficient (n) and forward rate constant (Ko f, h) Diffusion constant (Do 1/2) have also been calculated.