Molecular Modelling and Quantitative Structure-property Relationships (QSPRs) of Purine derivatives as Corrosion Inhibitor in Acid Medium

Abstract The corrosion inhibition potential of purine and its twelve derivatives was theoretically investigated. Their chemical descriptors: dipole moments, softness, electronegativity, chemical hardness, molecular weight in conjunction with the electronic parameters such as, EHOMO (highest occupied molecular orbital energy); ELUMO (lowest unoccupied molecular orbital energy) and energy difference (ΔE) which determine the effectiveness of the purine derivatives as corrosion inhibitors, were estimated using the Density Functional Theory (DFT) method. A statistically ordinary least square method was utilized to carry out the regression analysis that will infer the relationship between the quantum parameters and experimental corrosion inhibition efficiency. Predicted corrosion inhibition efficiencies of the studied purine derivatives were calculated using a developed QSPRs model. The calculated inhibition efficiencies are in good agreement with experimentally reported values with correlation coefficient of 0.9998 and root mean square error (%) of 1.1159. Verification of the developed model using both internal and external validations shows that the model is robust with good stability and predictability.