Revista de Ciencias Químicas

Quantum Descriptors and Corrosion Inhibition Potentials of Amodaquine and Nivaquine

Abstract

Adejoro IA , Ibeji CU and Akintayo DC

Amodaquine [4-[(7-chloroquinolin-4-yl) amino]-2-(diethylaminomethyl) phenol] and nivaquine (4-N-(7- chloroquinolin-4-yl)-1-N,1-N-diethylpentane-1,4-diamine sulphate) has been studied as potential source of green inhibitor for corrosion of aluminium in 1 M HCl at different concentrations using gravimetric method. To further elucidate the reactivity and efficiency of these anti-malaria drugs as potential corrosion inhibitors, quantum chemical calculations using Density Functional Theory (DFT) method in conjuction with Becke 3 Lee Yar Parr (B3LYP)/6-311++G** level of theory was applied. Kinetics and thermodynamic parameters central to surface adsorption were calculated and discussed. Results revealed that the inhibition efficiency increased as the inhibitor concentration increased but decrease with an increase in temperature with Nivaquine having better inhibition efficiency than Amodaquine. The adsorption of Amodaquine and Nivaquine on the surface of aluminium both followed the Freundlich adsorption isotherm at all concentrations and temperatures. The negative value of ΔGads obtained indicates spontaneous adsorption of the inhibitor on the aluminium surface and a low negativity indicates electrostatic interactions between inhibitor and the charged metal surface.