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The reaction of allyl chloride with the hydroxyl radical has been investigated on a sound theoretical basis. This is the first time to gain a conclusive insight into the reaction mechanism and kinetics for important pathways in detail. The reaction mechanism confirms that OH addition to the C=C double bond forms the chemically activated adducts, IM1 (CH2CHOHCH2Cl) and IM2 (CH2OHCHCH2Cl) via low barriers, and direct H-abstraction paths may also occur. Variational transition state model and multichannel RRKM theory are employed to calculate the temperature-, pressure-dependent rate constants. The calculated rate constants are in good agreement with the experimental data. At 100 Torr with He as bath gas, IM6 formed by collisional stabilization is the major products in the temperature range 200-600 K; the production of CH2CHCHCl via hydrogen abstractions becomes dominant at high temperatures (600-3000 K). [ABSTRACT FROM AUTHOR]

Mechanisms for the atmospheric degradation reaction of BrCH2O2 + HO2 were investigated using quantum chemistry methods. The result indicates that the dominant product is BrCH2OOH + O2(3Σ). While CH2O + HBr + O3, BrCHO + OH + HO2 and CH2O + Br + HO3 will be competitive to a certain extent in the atmosphere. Meanwhile, the nascent product – BrCH2OOH reacts easily with OH radicals leading to BrCH2O2 again under the atmospheric conditions. Moreover, OH radicals could act as a catalyst in the net reaction of BrCH2OOH → BrCHO + H2O. Thus the proposed product BrCHO + H2O + O2 in the experiment might be generated from the subsequent reaction of BrCH2OOH with extra OH radicals. Comparisons indicate that halogen substitution effect makes minor contributions to the XCH2O2 (X = H, F, Cl and Br) + HO2 reactions in the atmosphere. [ABSTRACT FROM AUTHOR]