Kinetics and mechanism of the gas phase reaction of chlorine atoms with i-propanol

Abstract

FTIR smog chamber techniques and ab initio calculations have been used to investigate the kinetics and mechanism of the reaction of Cl atoms with i-propanol in 700 Torr of N₂ at 296 K. The reaction is observed to proceed with a rate constant of k₁ = (8.28 ± 0.97) × 10⁻¹¹ cm³ molecule⁻¹ s⁻¹ and gives CH₃C(OH)CH₃ and CH₃CH(OH)CH₂ radicals in yields of 85 ± 7 and 15 ± 7%, respectively. Calculations indicate that abstraction of the secondary H can proceed through a lower energy pathway than the primary. Rapid decomposition of the chlorination product CH₃CCl(OH)CH₃ complicates its direct detection, likely due to heterogeneous chemistry. IR spectra for the chlorides CH₃CCl(OH)CH₃ and CH₃CH(OH)CH₂Cl were inferred experimentally and assignments confirmed via comparison with ab initio computed spectra.