A SHOCK-TUBE STUDY OF THE REACTION OF H-ATOMS WITH SICL4

The reaction of H atoms with SiCl4 was studied behind reflected shock waves at temperatures between 1530 K and 1730 K and pressures around 1 .5 bar by applying atomic resonance absorption spectroscopy (ARAS) for time resolved measurements of H atoms at the L-alpha-line. The therma l decomposition of a few ppm ethyl iodide (C2H5I) was used as a H-atom source. in the presence of a high excess of the molecular reactant Si Cl4 a slow consumption of H was observed, which follows a pseudo-first -order rate law. Rate coefficient for the consumption of H by the reac tion: (RI) H + SiCl4 -->(k1) SiCl3 + HCl was determined to be: k(1) = 1.4 x 10(13) exp(-4800 K/T) cm(3) mol(-1) s(-1). (C) 1997 John Wiley & Sons, Inc.