Photoreaction dynamics of permethylcyclohexasilane (Me2Si)(6) via triplet state surface: A direct MO dynamics study

摘要

The photoreaction mechanism of permethylcyclohexasilane via the excited triplet state potential energy surface, (Me2Si)(6) (T-1)-->(Me2Si)(5)+Me2Si:, has been studied by means of direct MO dynamics method with a full dimensional potential energy surface. In order to test the possibility of triplet state channel, we considered the reaction path on the triplet state surface in the present study. The total energy and energy gradient on each atom were calculated at each time step during the reaction by the PM3-MO method. The dynamics calculations suggested that the six-membered Si-ring is spontaneously changed to five-membered one and methylsilylene radical on the T-1 surface. The reaction was completed within 1.0 ps. The present calculations strongly indicated that the photochemical extrusion of silylene Me2Si from the Si-ring compounds is possible on the triplet energy surface as well as on the S-1 surface. (C) 1998 Elsevier Science S.A. All rights reserved. [References: 19]