Kinetics of the gas-phase reaction between iodine and trifluorosilane and the bond dissociation energy D(F3Si?H)

The title reaction has been investigated in the temperature range 667–715K. The only reaction products were trifluorosilyl iodide and hydrogen iodide. The rate law was obeyed over a wide range of iodine and trifluorosilane pressures. This expression is consistent with an iodine atom abstraction mechanism and for the step log k₁(dm³/mol·sec) = (11.54 ± 0.17) ? (130.5 ± 2.2 kJ/mol)/RT In 10 has been deduced. From this the bond dissociation energy D(F₃Si? H) = (419 ± 5) kJ/mol (100.1 kcal/mol) is obtained. The kinetic andthermochemical implications of this value are discussed.