The title isomerization of disilene, HXSi:SiH2 (X = 3h, 3d), was studied at the ab initio level. The energies of reactant, product, and transition state, their harmonic vibrational frequencies, and barrier energy were calculated The change in thermodn. functions, the equilibrium constant, and the rate constant for the isomerization reaction were also computed. The reaction is exothermic and spontaneous. This conclusion agrees with G. C. Newman et al. (1979) experimental results.

Key words: EQUILIBRIUM CONSTANT, KINETIC ANALYSIS, AB INITIO CALCULATION, ISOMERIZATION REACTION, REACTION RATE CONSTANT, SILYLENE, DISILANE P, THERMODYNAMIC ANALYSIS