Theoretical studies of the mechanism for the synthesis of silsesquioxanes.: 2.: Cyclosiloxanes (D3 and D4)

Several possible mechanisms for the synthesis of small ring systems, (H(OH)SiO)(n), (n = 3 and 4), the three- (D3) and four- (D4) membered cyclosiloxanes, respectively, are investigated with ab initio molecular orbital methods including electron correlation effects. It is found that the substantial potential energy barriers that must be overcome for these species to form are reduced to nearly zero in the presence of a water molecule that represents the solvent.