Structural and Solvent Dependence of the Electronic Properties and Corrosion Inhibitive Potentials of 1,3,4-thiadiazole and Its Substituted Derivatives- A Theoretical Investigation
O. E. Oyeneyin *
Department of Chemical Sciences, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria
*Author to whom correspondence should be addressed.
Abstract
The frontier molecular orbitals (FMOs) are very important for describing chemical reactivity and understanding the static molecular reactivity. The HOMO and LUMO energies of 1,3,4-thiadiazole and its substituted derivatives were calculated using the hybrid B3LYP method with a large polar 6-31G* basis set in vacuum, acetone, ethanol and tetrahydrofuran (THF). It was revealed that substitution at position -2 with -NO2, -CH3, -NH2, -CN and -CH=C(CN)COOH results in enhanced reactivities due to reduction of the energy band gap, Eg. It also altered some important molecular properties like η, S, ΔN, μ, α and β. Substituted -NO2, -CN and -CH=C(CN)COOH may possess better inhibitive potentials and better reactivities than other derivatives on the basis of studied parameters. It was observed that solvent media affect molecular properties.
Keywords: 1,3,4-thiadiazole, substituent effects, solvent effects, structural properties, electronic properties, global reactivity descriptors