pH Dependent Electrochemical Characterization, Computational Studies and Evaluation of Thermodynamic, Kinetic and Analytical Parameters of Two Phenazines

The electrochemical response of two biologically important phenazine derivatives was examined by using cyclic, differential pulse and square wave voltammetry in a wide pH range of 2.0 – 12.0. Cyclic voltammetry was employed for the determination of heterogeneous electron transfer rate constant and diffusion coefficient of the analytes. The value of electron transfer rate constant was used for evaluation of Gibbs free energy, enthalpy and entropy changes of redox reactions of the compounds. Differential pulse voltammetry was used for the determination of number of protons and electrons involved in the redox processes. Limits of detection and quantification were assessed by square wave voltammetry. The detailed pH dependent redox mechanisms of the compounds were proposed on the basis of experimental results which were further supported by theoretical calculations. These redox mechanistic pathways are expected to play a key role in understanding the necessary aspects of structure-activity relationships and exploring the hidden routes by which this class of compounds exert its biochemical actions.