"Front Matter". In: Organosilanes in Radical Chemistry - Index of

3 Hydrogen Donor Abilities of
Silicon Hydrides
The hydrogen abstraction from the Si w H moiety of silanes is fundamentally
important not only because it is the method of choice for studying spectroscopically
the silyl radicals but also because it is associated with the reduction of
organic molecules, process stabilizers and organic modification of silicon surfaces.
This chapter focuses on the kinetics of reactions of the silicon hydrides with
radicals. Kinetic studies have been performed with many types of silicon
hydrides and with a large variety of radicals. The data can be interpreted in
terms of the electronic properties of the silanes imparted by substituents for
each attacking radical. Therefore the carbon-, nitrogen-, oxgygen-, and sulfurcentred
radicals will be treated separately followed by a section on ketone
triplets. It is worth mentioning that the reactivity of atoms and small organic
radicals with silanes in the gas phase has been studied extensively. Although we
deal in this chapter mainly with organic radicals in solution, the reactions of
hydrogen atom with some silanes will be given as examples of gas-phase
chemistry. Theoretical models for calculating activation energies will also be
considered.
The kinetic data reported in this chapter have been determined either by
direct measurements, using for example kinetic EPR spectroscopy and laser
flash photolysis techniques or by competitive kinetics like the radical clock
methodology (see below). The method for each given rate constant will be
indicated as well as the solvent used. An extensive compilation of the kinetics
of reaction of Group 14 hydrides (R3SiH, R3GeH and R3SnH) with radicals is
available [1].
Organosilanes in Radical Chemistry C. Chatgilialoglu
# 2004 John Wiley & Sons, Ltd ISBN: 0-471-49870-X