Theoretical study of the structure and tautomerism of an asymmetric diimine Schiff base, preparation and characterization of its modified electrode

Abstract

An asymmetric diimine Schiff base, 2-((E)-4-((E) -2-hydroxybenzylideneamino) benzylideneamino) phenol, was covered to a glassy carbon (GC) electrode surface in nonaqueous medium to fabricate a modified electrode. Cyclic voltammetry was applied for the surface modification experiments in 1 mM diimine solution. Cyclic voltammetry, contact angle measurement, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy techniques were employed to characterize the modified GC (diimine-GC) surface. Electrochemical impedance results showed that the modified surface blocked the electron transfer with a 98.9% surface coverage value. Additionally, theoretical study was performed to gain insight into the structural and tautomeric aspects of the diimine Schiff base. The phenol-imine and keto-amine tautomerism forms of the diimine Schiff base were investigated by using DFT calculations.