RATE CONSTANTS FOR THE GAS-PHASE REACTIONS OF OH AND NO3 RADICALS AND O-3 WITH SABINENE AND CAMPHENE AT 296+/-2-K

The rate constants for the gas-phase reactions of sabinene and camphene, two monoterpenes emitted from vegetation, with OH and NO3 radicals and O3 have been determined at 296±2 K and one atmosphere total pressure of air. The OH and NO3 radical reaction rate constants were determined using relative rate techniques. Using rate constants of k(OH + isoprene) = 1.01 × 10-10 cm3 molecule-1 s-1, k(NO3 + trans-2-butene) = 3.87 × 10-13 cm3 molecule-1 s-1 and k(NO3 + 2-methyl-2-butene) = 9.33 × 10-12 cm3 molecule-1 s-1, the following OH and NO3 radical reaction rate constants (in cm3 molecule-1 s-1 were obtained: OH radical reaction; sabinene, 1.17 × 10-10 and camphene, 5.33 × 10-11; NO3 radical reaction; sabinene, 1.01 × 10-11, and camphene, 6.54 × 10-13. The absolute O3 reaction rate constants determined were (in cm3 molecule-1 s-1 units): sabinene, 8.07 × 10-17, and camphene, 9.0 × 10-19. These rate constants are compared to literature data for other structural-related alkenes and monoterpenes. © 1990.