Atmospheric reactions of methylcyclohexanes with Cl atoms and OH radicals: determination of rate coefficients and degradation products.

As the result of biogenic and anthropogenic activities, large quantities of chemical compounds are emitted into the troposphere. Alkanes, in general, and cycloalkanes are an important chemical class of hydrocarbons found in diesel, jet and gasoline, vehicle exhaust emissions, and ambient air in urban areas. In general, the primary atmospheric fate of organic compounds in the gas phase is the reaction with hydroxyl radicals (OH).

Kinetics and mechanisms of the tropospheric reactions of menthol, borneol, fenchol, camphor, and fenchone with hydroxyl radicals (OH) and chlorine atoms (Cl).

Relative kinetic techniques have been used to measure the rate coefficients for the reactions of oxygenated terpenes (menthol, borneol, fenchol, camphor, and fenchone) and cyclohexanol with hydroxyl radicals (OH) and chlorine atoms (Cl) at 298 ± 2 K and atmospheric pressure. The rate coefficients obtained for the reactions of the title compounds with OH are the following (in units of 10(-11) cm(3) molecule(-1) s(-1)): (1.48 ± 0.

Daytime reactions of 1,8-cineole in the troposphere.

Relative rate coefficients for the gas-phase reaction of chlorine atoms (Cl) and hydroxyl radicals (OH) with 1,8-cineole were determined by Fourier-transform infrared (FTIR) spectroscopy between 285 and 313 K at atmospheric pressure. The temperature dependence of both reactions shows simple Arrhenius behaviour which can be represented by the following expressions (in units of cm(3) molecule(-1) s(-1)): k(1,8-cineole+OH)=(6.28 ± 6.

Atmospheric reactions of (H)- and (D)-fluoroalcohols with chlorine atoms.

The reactions of Cl with a series of fluoroalcohols and deuterated fluoroalcohols, CF(3)CH(2)OH (k(4)), CF(3)CH(OH)CH(3) (k(5)), CF(3)CH(OH)CF(3) (k(6)), CF(3)CH(OD)CF(3) (k(7)) and CF(3)CD(OD)CF(3) (k(8)), are investigated as a function of temperature in the range of 268-378 K by laser photolysis-resonance fluorescence. To our knowledge, only the CF(3)CH(2)OH + Cl reaction has been previously studied from a kinetic point of view. The derived Arrhenius expressions obtained using our kinetic data are: k(4) = (1.

Molecular structure, vinyl rotation barrier, and vibrational dynamics of 2,6-dichlorostyrene. A theoretical and experimental research.

The molecular structure of 2,6-dichlorostyrene has been analyzed at MP2 and DFT levels using different basis sets concluding in a nonplanar geometry. The influence of either the level of theory or the nature of the substituent has been assessed. The vinyl-phenyl torsion barrier has also been investigated as a function of level of theory.