Inhibitory Effect of Some Methylxanthines on Copper Corrosion in 1M HNO3: Experimental, DFT and QSPR Studies

The effect of methylxanthines on copper corrosion inhibition in 1M HNO 3 was investigated by mass loss measurements and by two theoretical approaches: Density Functional Theory (DFT) and Quantitative Structure Property Relationship (QSPR.) Quantum chemical calculations based on DFT at the B3LYP/6-31G(d) level permit to establish a correlation between the quantum chemical parameters and the experimental inhibition efficiency (IE %). It was found that inhibition efficiencies increase with increasing temperature and immersion time. In addition, QSAR approach was used to find the best set of parameters for each molecule. These set of parameters make it possible to characterize the inhibition performance of the tested molecules solution significantly. The theoretical calculations are consistent with the experimental results.