Theoretical Study on the Ethynethiol and Ethynedithiol Molecules

Abstract

The equilibrium geometries , heat of formations, dipole moments , ionization
energies, HOMO- LUMO orbital energies, charge and electron densities , and the ir
spectra for ethynethiol and ethynedithiol molecules were evaluated theoretically .The
calculation method was based on the semi-empirical MINDO/3-FORCES MO
method. In comparison with ethynethiol , the second molecule has the lower values
for both frequency and ir intensity values of the fundamental vibration localized at the
CC bond and , also, it has the higher value for the frequency of the other fundamental
concentrated at the CS bond. This effect may be due to the resonance effect caused by
the S atom