Potential-energy surfaces in singlet and triplet silylene

Abstract

MC SCF calculations with the 6-31G ** basis set, augmented by second-order configuration interaction, are used to analyze the potential-energy curves in the lowest singlet and triplet states of SiH 2. The adiabatic singlet-triplet splitting is predicted to be 17.7 kcal/mol, and the curves are predicted to cross at ≈ 129°. Thus, bulky substituents may open the angle in the singlet sufficiently to invert the ordering of the two states.