Electronic structure of planar-quasicycled organic molecules with intramolecular hydrogen bond

Abstract

By means of the HF/6-311G(d,p) method, the electronic structure of the series of organic molecules, among which are malonaldehyde, acetylacetone, thiomalonaldehyde,’the derivatives of aniline 2-XC6H4NH2, phenol 2-XC6H4OH, benzenethiol 2-XC6H4SH (X = CHO, COOH, COO-, NO, NO2, OH, OCH3, SH, SCH3, F, Cl, Br), 8-hydroxyquinoline, 8-mercaptoquinoline, tropolone, has been studied. The intramolecular hydrogen bond (IHB) has been established to lead to a local electron redistribution in quasicycle, and primarily to the electron density transfer between the direct IHB participants – from the hydrogen atom toward the proton-aceptor atom. On forming the IHB of the S–H···O type, the electron density in general decreases on the sulphohydryl hydrogen atom and increases on the sulphur atom.

Keywords

• intramolecular hydrogen bond
• electronic structure
• organic compounds with planar quasicycle
• quantum chemical ab initio study
• dipole moment