Studies on the Inelastic Electron Tunneling Spectroscopy of o-Hydroxy-, o-Amino-, and o-Mercaptobenzoic Acid on Aluminium Oxide

Abstract

Abstract Inelastic electron tunneling (IET) spectra were obtained for o-hydroxybenzoic acid(OHBA), o-aminobenzoic acid (OABA) and o-mercaptobenzoic acid (OMBA) adsorbed on aluminium oxide (AlOx) grown on aluminium film and were analyzed by referring IR results. OHBA is adsorbed on AlOx with both two functional groups, carboxyl and hydroxyl radicals. In the case of OABA, the adsorption occurs mainly with carboxyl group and the interaction between amino group and AlOx is rather weak. Mercapto group of OMBA forms two kinds of hydrogen bonding, and a dissociated species on AlOx. These results indicate that the surface of AlOx used in this study is highly hydrated and hydroxyl groups on the oxide are reactive with the proton donating sites of the chemical species. IET spectra of o-fluoro- and o-chlorobenzoic acid were also observed for comparison.