Structures, vibrational spectra, and relative energies of HXSiS (X = H, F,and Cl) isomers

The potential energy surface for the decomposition of HXSiS (X = H, F, and C1) on the singlet state has been explored by B3LYP and CCSD(T) calculation s. Five different types of reaction are proposed: (A) 1,1-HX elimination, ( B) 1,2-H shift, (C) 1,2-X shift, (D) H . and XSiS . radical formation, and (E) X . and HSiS . radical formation. These results show interesting trends for the HXSiS isomers. Our theoretical investigations suggest that the dou bly bonded species KXSi=S should be the lowest energy structure among the i somers from both kinetic and thermodynamic viewpoints. We also report theor etical predictions of molecular parameters and vibrational infrared (IR) sp ectra of the monohalogen-substituted silanethione, which should be useful f or future experimental observations. (C) 2001 John Wiley & Sons, Inc.