The kinetics of reactions of chlorine, bromine, bromine monochloride, iodine monochloride, and iodine monobromide with phenyltrimethylsilane

Abstract

Halogens and interhalogens, XY, react with PhSiMe3 in 98.5% aqueous acetic acid to give (Me3Si)2O, H+, Y–, and PhX (X = Y = Cl, Br; X = Br, Y = Cl; X = I, Y = Br or Cl). Kinetic measurements at 30.0 °C show that all reactions are first order in PhSiMe3, reactions with BrCl and Cl2 are first order in halogen, reactions with ICl and IBr are second order in halogen, and reactions with Br2 involve both first- and second-order terms. Rate coefficients for all the reactions are reported. The kinetics of the reactions of Br2, ICl, and IBr are complicated by formation of trihalide complexes between the halogen and halide ion product. The formation constants for these complexes have been measured, and a numerical integration method is described to calculate the rate coefficients for these halogenations from the experimental data.