Effect of substituents in 5-R-3-amino-1,2,4-triazoles on the chemisorption on copper surface in neutral media

Using a complex of physical and electrochemical methods, the effect of R-substituent on the adsorption of 5-R-3-amino-1,2,4-triazoles on copper surface in neutral buffer solution was studied. Minimum concentrationsC(min), which suppresses the first anodic peak of copper dissolution were found, and two different linear correlations of logC(min)values on induction constant sigma(I)were plotted: for compounds with electron-donor and electron-withdrawing ones. Using ellipsometry, free adsorption energies -Delta G(a,max)(0)were determined. It was shown that adsorption of triazoles with electron acceptor R, which have the highest sigma(I), occurs at very low concentrations and -Delta G(a,max)(0)= 96.6 kJ mol(-1)that is higher than for inhibitors of the same reaction series, but with electron-donor R (70 divided by 85 kJ mol(-1)). In this case, monolayers are formed, whose thicknesses are close to molecule size. The formation of chemisorption bonds is confirmed using XPS by studying the composition of adsorption layers formed by 5-CF3-3-amino-1,2,4-triazole on the copper surface.

Automated summary

Using a combination of physical and electrochemical methods, this study examined the influence of R-substituent on the adsorption of 5-R-3-amino-1,2,4-triazoles on copper surfaces in neutral buffer solution. The research identified minimum concentrations that suppress copper dissolution and determined free adsorption energies for different types of compounds based on the R-substituent. The results showed that the adsorption characteristics of triazoles were dependent on the nature of the substituent, with electron acceptor R resulting in higher adsorption at lower concentrations.