title: Natural polyprenylated benzophenone: keto-enol tautomerism from density functional calculations and the AIM theory.
abstract: The quantum theory of atoms in molecules (QTAIM) and density functional theory (DFT) calculations were employed to investigate the structure and tautomeric equilibrium of epiclusianone, a polyisoprenylated benzophenone with interesting biological activities. Two different exchange-correlation functionals were employed, namely ωB97x-D and M06-2x, including implicit solvent models (benzene and DMSO). Our results for the thermodynamic properties show that the isomer in which the H atom is bonded to the oxygen away from the benzene ring is the most stable tautomer form of the epiclusianone, thus confirming previous charge density analysis from X-ray diffraction data (Martins et al. J Braz Chem Soc 18(8):1515-1523, 22).
authors.affiliation: Universidade Federal do Maranhão, Campus Balsas, Rua José Leão, 484, Centro, Balsas, MA, CEP:65800-000, Brazil.
authors.forename: Mateus R
authors.initials: MR
authors.lastname: Lage
authors.affiliation: Faculty of Physics, University of Duisburg-Essen, Duisburg, Germany.
authors.forename: Juliana M
authors.initials: JM
authors.lastname: Morbec
authors.affiliation: Instituto de Química, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors.forename: Marcelo H
authors.initials: MH
authors.lastname: Santos
authors.affiliation: Instituto de Química, Universidade Federal Fluminense, Outeiro de São João Batista, s/n, CEP:24020-141, Niterói, RJ, Brazil.
authors.forename: José Walkimar
authors.initials: JW
authors.lastname: de M Carneiro
authors.affiliation: Instituto de Química, Universidade Federal Fluminense, Outeiro de São João Batista, s/n, CEP:24020-141, Niterói, RJ, Brazil. ltcosta@id.uff.br.
authors.forename: Luciano T
authors.initials: LT
authors.lastname: Costa
keywords: DFT; Epiclusianone; QTAIM; Tautomerism