Quantum-chemical study of the effects of stabilization of 1,3-di(silylmethyl)imidazol-2-ylidene and its halo-substituted analogs due to the interaction of Si-coordination and carbene centers

A potential surface of rotational transformations of 1,3-di(silylmethyl)imidazol-2-ylidene and its halo-substituted analogs has been analyzed using quantum-chemical methods. Coordination interactions of the carbene center with Si-fragments have been studied. It is shown that the above interaction results in a structural reorganization of the silicon centers from the tetrahedral state to the trigonal-bipyramidal. This leads to a considerable stabilization of compounds in the planar state. The stabilization effect is strengthened by halogenation.