Gas-phase reactions of Cl atoms with hydrochloroethers: relative rate constants and their correlation with substituents' electronegativities

P. DALMASSO, R. TACCONE, J. NIETO, P. COMETTO AND S. LANE

JOURNAL OF PHYSICAL ORGANIC CHEMISTRY

Año: 2007

0894-3230

The potential interference by OH radicals in the determination of the rate constants for the reactions of Cl atoms with CH3OCHCl2 and CH3OCH2CH2Cl carried out in air, was assessed at (296 ± 2) K and atmospheric pressure using synthetic air as bath gas. Decay rates of these organic compounds were measured relative to the following reference compounds: CH2ClCH2Cl  and n-C5H12. Using rate constants of 1.33 x 10-12 and 2.52 x 10-10 cm3 molecule-1 sec-1 for the reaction of Cl atoms with CH2ClCH2Cl and n-C5H12 respectively, the following rate coefficients were derived: k(Cl + CH3OCHCl2) = (1.05 ± 0.11) x 10-12  and k(Cl + CH3OCH2CH2Cl) = (1.14 ± 0.10) x 10-10, in units of cm3 molecule-1s-1. The rate constants obtained were compared with previous literature data and a correlation was found between the rate coefficients of some CH3OCHR1R2 + Cl reactions and ∆Electronegativity of -CHR1R2.     Keywords:  Relative rate constants - Hydrochloroethers – Chlorine atoms – Hydroxyl radical interference - Electronegativity