Collect. Czech. Chem. Commun. 1979, 44, 2092-2095

Some chemical reactions of sulfur hexafluoride with silicon containing species stimulated by cw CO2 laser radiation

Josef Polaa, Pavel Engstb and Milan Horákb

a Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6-Suchdol
b The J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 121 38 Prague 2


The CO2 cw laser induced interaction of sulfur hexafluoride with chlorine, silicon tetrachloride, trichlorosilane, and methyltrichlorosilane in a glass reaction vessel has been investigated. The reaction of SF6 with glass surface yielding silicon tetrafluoride and thionyl fluoride was observed. It is inhibited by the products and its rate increases with growing initial pressure (0.6-5.3 kPa) of SF6. Presumed vibrationally excited or dissociated SF6 undergoes the same reaction in the presence of chlorine and silicon tetrachloride, too. The reaction is suppressed by the addition of trichlorosilane and methyltrichlorosilane; in these cases SiF4, SiCl4 and HCl, or SiF4, SiCl4, HCl, acetylene and carbon disulfide are formed. The products indicate a non-sensitizing action of SF6 and a specific reaction channel for the formation of CS2 not attainable by pyrolysis.