Theoretical Study of New Derivative of Cefotaxime-Amic Acid as a Corrosion Inhibitor

Abstract

PM3 and DFT quantum mechanical calculations were employed to give further
insight into the inhibition efficiency of the newly prepared cefotaxime amic acid
derivative. The calculated physical properties and quantum chemical parameters
correlated to the inhibition efficiency such as EHOMO (highest occupied molecular
orbital energy), ELUMO (lowest unoccupied molecular orbital energy), the energy gap
(ΔE(HOMO-LUMO)), hardness (η), softness (S), dipole moment (μ), electron affinity
(EA), ionization potential (IE) and active site absorption..…etc., all studied and
discussed at equilibrium geometry in the gas phase and at its right symmetry (C1).
Experimentally the newly prepared cefotaxime derivative could be absorbed on
carbon steel surface with good inhibition efficiency by offering electrons from rich
hetero-atoms such as nitrogen and oxygen to unoccupied d-orbitals of Fe metal and
forming antibonding orbital-feedback bonds.