The vibrational spectra of the boron halides and their molecular complexes. Part 9. Ab initio studies of the complexes of boron trifluoride with methanol, methanethiol and some related bases

The structures, interaction energies and vibrational spectra of the electron donor-acceptor complexes formed between boron trifluoride, as Lewis acid, and methanol and methanethiol, as Lewis bases, have been determined by means of ab initio calculations at the level of second order Møller–Plesset perturbation theory, using a triple-zeta Gaussian basis set with polarization and diffuse functions on all atoms. Two conformers, an eclipsed and a staggered species, have been examined for each complex, and the preferred conformer identified in each case. The computed data have been compared with those for some related complexes containing boron trifluoride and other oxygen and sulphur electron donors (water, hydrogen sulphide, dimethyl ether and dimethyl sulphide).