Ring opening of silacyclobutane

Initial cleavage of a ring CC bond to form a trans .CHsub2SiHsub2Chsub2Chsub2. diradical is the most likely route from silacyclobutane to ethylene + silene, according to multiconfigurational self-consistent field wave functions and second order perturbation theory. The trans diradical is predicted to be a minimum on the MCSCF ground state potential energy surface. The addition of dynamic correlation leads to the disappearance of the transition state.