Experimental and Theoretical Investigations on Copper Corrosion Inhibition by Cefixime Drug in 1M HNO3 Solution

Cefixime, a third-generation semi-synthetic cephalosporin antibiotic was used as copper corrosion inhibitor in 1M HNO3 solution. The study conducted through the weight loss technique at 298 - 318 K and theoretical studies based on quantum chemistry. studied drug inhibited of over cefixime concentration range (0.02 2 mM). inhibition efficiency increased with an increase to reach 91.07% mM, but decreased temperature. thermodynamic functions related adsorption surface that metal dissolution were computed analyzed. results point out spontaneous adsorption, mainly physisorption mechanism following Langmuir isotherm model endothermic process. Quantum chemical calculations also performed B3LYP level 6-31G (d, p) basis set lead molecular descriptors such EHOMO (energy highest occupied orbital), ELUMO lowest unoccupied ΔE gap) μ (dipole moment). global reactivity χ (electronegativity), (global hardness), S softness), ω (electrophilicity index) derived using Koopman’s theorem local parameters, including Fukui dual determined discussed. Experimental found be good agreement.