Estudo das ligações de hidrogênio para dímeros formados pelas moléculas de H2O, NH3, HF, HCl e HBr através de cálculos baseados em primeiros princípios

Abstract

HYDROGEN BOND STUDY BY AB INITIO CALCULATIONS FOR DIMERS FORMED FROM H2O, NH3, HF, HCl AND HBr MONOMERS. Hydrogen bond energies of fifteen dimers were calculated using the large basis set 6-311++G(3df,3pd), at HartreeFock (HF) level including Moller-Plesset (MP2) calculations. The procedure for obtaining such energies were based on the dimer’s energy rise provoked by increasing in intermolecular distance of the system component units. Deviations from a strictly linear hydrogen bond were investigated and rotational barriers were also computed allowing the calculation of the second order attractive interactions. In order to provide a more objective definition of hydrogen bond, a lower energy limit was proposed in place of the merely empirical parameters employed in the classical definition.