THEORETICAL STUDY OF 2 - (3, 4-DIHYDROXYPHENYL) CHROMAN-3, 5, 7-TRIOL ON CORROSION INHIBITION OF MILD STEEL IN ACIDIC MEDIUM

Abstract

Corrosion inhibitive effect of 2 - (3, 4-dihydroxyphenyl) chroman-3, 5, 7-triol (DCT) has been studied using quantum chemical calculations and molecular dynamic simulation techniques. The quantum chemical calculations were carried out using Material Studio version 8.0. It was performed to characterize the electronic descriptors which were responsible for the inhibitor interaction with metal using density function theory at Becke three Yarg and Parr with 6-311G++ (d, p) basis set as B3LYP/6-311G++ (d, p). Quantum chemical parameters such as , dipole moment and total negative energy charge on molecules e.t.c. were calculated. From the results calculated, the values of X, I, A, S and  for DCT are given as 0.106au, 0.204au, 0.008au, 10.204au, 0.098au respectively. Molecular dynamic simulation was performed with Forcite field quench module, using COMPASS (version 2.8) force field to study the mechanism of the process and the interaction between the molecule and the metal surface respectively. The binding energy ( ) between the metal surface and the inhibitor molecules was calculated and was found to be -24.31kcalmol^-1 suggesting stable adsorption structure however; the magnitude of the calculated binding energy is < 100 kcal mol⁻¹ which implies physisorptive interactions.  The results obtained from computational methods revealed that DCT acts as good inhibitor and could serve as an effective corrosion inhibitor. Also from the molecular dynamic simulation it shows that the inhibitor could adsorb onto mild steel surface.