Theoretical evaluation of corrosion inhibition performance of two new thiocarbohyrazides

Inhibition efficiencies of two newthiocarbohyrazides (N,N'-[2,2'-thiocarbonylbis(hydrazine-2,1- diyl) bis (thioxomethylene)] dibenzamide(T0) and N,N'-[2,2'-thiocarbonylbis(hydrazine-2,1-diyl) bis (thioxomethylene)] bis(4-methoxybenzamide)(T6)) has been studied on corrosion of carbon steel using densityfunctional theory (DFT) method in gas phase. Quantum chemical parameters such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupiedmolecular orbital energy), hardness (η), dipole moment (μ), polarizability (α), electronegativity (χ), global electrophilicity index (ω)and the fraction of the transferred electron (ΔN)have been calculated at the B3LYP level of theory with 6-311++G ** basis set. Inconsistent with experimental data, theoretical results showed that the order of inhibition efficiency is T2>T1.

Keywords:

Corrosion inhibition , Density functional theory (DFT) , thiocarbohyrazides