Ab initio studies on the structures and isomerization of the carbenoids CH2LiX (X = F, Cl)

The potential energy surface of the singlet carbenoid H2CLiCl has been examined using ab initio methods including electron correlation. The 6–31G∗ basis set was used for all geometry optimizations. Three equilibrium structures and two isometrc transition states were located, but only the lowest energy structure with a three-membered ring should be experimentally observable and take part in chemical reactions. In addition, CH2LiF has been re-examined and it was found that isomerization of the structure with p-complex form to the structure with three-membered ring form was more reasonable via a rotational transition state than an inversion transition state.