Theoretical Studies On Tautomerization And Electronic Spectra Of Salicylanilide

The intramolecular proton transfers are one of the fundamental and important processes in life and nature. The study of some model compounds can favour people's understanding to the basic process, and the related study has become one of modern fields in physical chemistry research. Many moleculars hold more than one geometries or tautomerisms. Except for intramolecular proton transfer, the conformational isomerization is one important mode of tautomerism, too. The pharmacology activities of substances used as medicines have closed relations with moleculars' geometries and conformations, different conformations of the same molecular may have remarkably different activitiys. Salicylanilide has very good bactericidal and fungicidal activities , which can be used as antiseptics or medicines. furthermore,it also can be made into ointments. Moreover, salicylanilide molecular has many tautomeric forms. therefore, the study to the tautomerization of salicylanilide molecular is necessary.Electronic spectra, which belongs to absorption spectra , is produced because of the electron'transition from ground-state to excited-state. Electronic spectra is one importent propertie of molecular. Investing electronic spectra is one very important way to conforming molecular structure and probing molecular properties.Salicylanilide has been applied into many ways, for example, bactericide, fungicide, medicine and model compound in the study of intramolecular proton transfer. as so far, people have made a lot of studies in the terms of experiment, but no article investidating salicylanilide in the terms of quantum chemistry theory. Therefore, in this article we attempted to investigate salicylanilide in the terms of quantum chemistry theory.In this paper we used B3LYP/6-31+G* theoretical method to study the tautomerism of salicylanilide. The 20 ground-state structures and 28 transition-state structures of salicylanilide were fully optimized at B3LYP/6-31+G* level. The frequency analysis was performed on all the optimized structures. For the ground-state geometries, all the calculated...