Proton Affinity and Heat of Formation of Silylene

Article abstract of DOI:10.1021/j100399a009

Using the techniques of Fourier transform ion cyclotron resonance spectroscopy, we determined the proton affinity of silylene to be 201 +/- 3 kcal*mol^-1 from a study of the kinetics and thermochemistry of proton transfer from SiH3⁺ to a series of n-donor bases with well-established gas-phase base strengths.This value leads to ΔH_f^o₂₉₈(SiH2) = 69 +/- 3 kcal*mol^-1, which is 11 kcal*mol^-1 higher than the previously accepted value (Wals, R.Acc.Chem.Res. 1981, 14, 246-252), but in excellent agreement with the recent theoretically recommended value of 68.1 kcal*mol^-1 (Ho, P.; Coltrin, M.E.; Binkely, J.S.; Melius, C.F.J.Phys.Chem. 1985, 89, 4647-4654).