The Quantum Chemical Calculations of Some Thiazole Derivatives

Abstract

An examination of quantum chemical and corrosion inhibition studies for some thiazole derivatives, namely 2-amino-4-(p-tolyl)thiazole (APT), 2-methoxy-1,3-thiazole (MTT) and thiazole-4-carboxaldehyde (TCA) had been tested as corrosion safe inhibitors for mild steel (CRS) in 0.5 M H2SO4 solutions at 25 °C temperature. The correlation between inhibition efficiency and descriptor variables obtained from the quantum chemical calculation using B3LYP/6-311G(d,p), B3LYP/6-311++G(2d,2p), and CBS-APNO methods. Result showed that APT could have better performance as corrosion inhibitor for the non-protonated and protonated for gas and solvent phase compounds using CBSQ method. The results of the highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), the energy gap between ELUMO and EHOMO (ΔE), dipole moments (DM), molecular volume (MV), sum of the total negative charge (TNC), global hardness (η), softness (σ), electronegativity (χ), chemical potential (μ), Global Electrophilicity (ω) and sum of electronic and zero-point energies (SEZPE) of three methods are compatible with each other very well.