Effect of Coordination of Germabenzenes to Cr(CO)3 on Their 1,2- and 1,4-Addition Reactions with Water

Abstract

The mechanism and potential energy surface of the 1,2- and 1,4-addition reactions between germabenzenes and H2O were investigated by using density functional theory (DFT) calculations at the MPW1K/6-311++G(d,p) level. The influence of coordination of germabenzene to Cr(CO)3 on the energy surface was also explored. The obtained results indicate that all of monomer, dimer and trimer of H2O can react with germabenzenes as nucleophiles. Addition reactions involving the dimer of H2O occur more favorably than those related to H2O monomer and trimer kinetically. The coordination of germabenzene to Cr(CO)3 has a much unfavorable effect on the thermodynamic properties, especially for 1,4-addition. The modest regioselectivity observed experimentally for the addition involving free germabenzene is controlled by kinetic factor, however, for the addition of H2O to germabenzene–Cr(CO)3 complexes, the complete regioselectivity may be related to both thermodynamic and kinetic factors.