An FTIR Study of the Kinetics and Mechanism for the Cl- and Br-Atom-Initiated Oxidation of SiH4

Article abstract of DOI:10.1021/j100255a042

On the basis of FTIR product analysis of the UV-visible (λ <*> 300 nm) photolysis of Cl2-SiH4 and Br-SiH4 mixtures in 700 torr of N2-O2, both Cl and Br atoms were shown to exclusively undergo an H-atom abstraction reaction rather than a displacement reaction with SiH4.The corresponding rate constants k and k were determined at 298 K to be 4.4E-10 and 1.0E-13 cm³ molecule^-1 s^-1, respectively, by the competitive kinetic method with reference to the reactions Cl + C3H8 and Br+CH2O.IR absorption bands attributable to an aerosol product were detected in the subsequent oxidation of the primary radical SiH3.This product was tentatively identified as a polymeric form containing the <-HSi(OH)O-> group.A possible mechanism for its formation is discussed.