ATMOSPHERIC CHEMISTRY OF THE MONOTERPENE REACTION-PRODUCTS NOPINONE, CAMPHENILONE, AND 4-ACETYL-1-METHYLCYCLOHEXENE

Rate constants for the gas-phase reactions of OH radicals with nopinone (6,6-dimethylbi-cyclo[3.1.1]heptan-2-one) and camphenilone (3,3-dimethylbicyclo[2.2.1]heptan-2-one) and for the reactions of 4-acetyl-1-methylcyclohexene with OH and NO3 radicals and O3 have been measured at 296 +/- 2 K. The rate constants (cm3 molecule-1 s-1 units) obtained were, for reaction with the OH radical: nopinone, (1.43 +/- 0.37) x 10(-11); camphenilone, (5.15 +/- 1.44) x 10(-12); and 4-acetyl-1-methylcyclohexene, (1.29 +/-0.33) x 10(-10); for reaction with the NO3 radical: 4-acetyl-1-methylcyclohexene, (1.05 +/- 0.38) x 10(-11); and for reaction with O3: 4-acetyl-1-methylcyclohexene, (1.50 +/- 0.53) x 10(-16). These data are used to calculate the tropospheric lifetimes of these monoterpene atmospheric reaction products.