Bond dissociation energies: electron impact studies on some trimethylsilyl compounds

Abstract

From appearance potential measurements, the following bond dissociation energies, D(Me₃Si–X) in kcal. mole^–1, have been determined: Me₃SiMe, 76 ± 2; Me₃SiH, 81 ± 2; Me₃SiCl, 88 ± 2; Me₃SiBr, 78·5 ± 2; and Me₃Sil, 69 ± 2. Heats of formation have also been deduced (the heat of formation of the trimethylsilyl radical is –25·6 kcal. mole^–1), and some approximate ionisation potentials for molecules and radicals are given. Some deductions about bonding in silicon compounds are made.