STUDIES ON THE CORRELATION BETWEEN ELECTRONIC-STRUCTURE AND CORROSION-INHIBITING PROPERTIES OF ISOQUINOLINE AND ITS DERIVATIVES

The corrosion-inhibiting efficiencies of isoquinoline and its hydroxyl and carboxyl derivatives on Fe electrode in HCl solution have been determined with electrochemical method. their structure parameters were obtained by means of HMO and CNDO/2 methods. It is found that the lees the net charge and pi charge of N atom has, the more the inhibition efficiency is. As the net charge sum of six atoms in pyridine ring increases, the efficiency increases. It is possible that the molecules of the inhibitors were adsorbed on the surface of Fe electrode in horizontal state.