Theoretical evaluation of corrosion inhibition performance of three antipyrine compounds

Corrosion inhibition performance of three antipyrine derivatives namely, 4-amino-antipyrine (AAP), 4-[(4-hydroxy benzylidene)-amino]-antipyrine (SAAP) and 4-[(4,methoxy benzylidene)-amino]-antipyrine (AAAP), for metal surface corrosion was studied by using quantum chemistry, molecular mechanics and molecular dynamics simulation methods. Correlations between the quantum chemical parameters (E-HOMO, E-LUMO, the energy gap, global hardness, global softness and Fukui index) and experimentally determined inhibition efficiency have been carried out and discussed. The adsorption behavior of APP, SAAP and AAAP on metal surface was studied using molecular dynamics simulation methods, through which the binding energy was obtained. The order is as follows: AAAP > SAAP > AAP, which is well accorded with the result (inhibition efficiencies) obtained from the experiments. (C) 2015 Elsevier B.V. All rights reserved.