THEORETICAL-STUDIES OF CYCLOPROPYLSILYLENES - THE REARRANGEMENT OF CYCLOPROPYLSILYLENE C3H5SIH

The rearrangement of cycyclopropylsilylene C3H5SiH have been studied b y ab initio molecular orbital theory at 3 - 21G and 6 - 31G levels. C orrelation energy corrections were computed with using second - order Moller - Plesset perturbation theory (MP2). The enthalpy Delta H, free energy Delta G, equilibrium constant K, and reaction rate constant k( T) in Eyring transition state theory of cyclopropylsilylene C3H5SiH ha ve also been calculated. The results show that the ring expansion of c yclopropylsilylene C3H5SiH to silacyclobutene is easy to occur with a barrier of 113.4kJ/mol, while the 1,2 - H shift is not competitive to the ring expansion for its muchhigher barrier. The rearrangement is di vided into several steps and each step can be explained with Woodward - Hoffmann rule.