Rate Constants for the Reactions of O(P) with Selected Monoterpenes

Rate constants for the gas phase reactions of O(P) atom with a series of monoterpenes have been determined at ambient temperature (~302-309K) and atmospheric pressure using a relative rate technique. Using the literature rate constants for O(P) + isobutene, cis and trans-2-butene, 3-methyl-1-butene, 2-methyl-2-butene and 2,3-dimethyl-2-butene as the standards, the O(P) rate constants derived for the terpenes (in units of 10 cmmolecules) are 2.8±0.4 for α-pinene, 2.8±0.5 for β-pinene, 3.1±0.5 for ∆-carene, 3.5±0.5 for 2-carene, 2.6±0.5 for camphene, 7.6±1.2 for d-limonene, 9.0±1.6 for γ-terpinene and 10.7±1.6 for terpinolene. The relative rate constants in this work agreed with literature values to within ±10% for the standard alkenes, and to within ±~35% for the terpenes. Compound Index: O(P), α-pinene, β-pinene, ∆-carene, 2-carene, camphene, d-limonene, γ-terpinene, terpinolene, 2-methyl-2-butene, isobutene, cis-2-butene, trans-2-butene, 3-methyl-1-butene, 2,3-dimethyl2-butene Subject Index: O(P) rate constants, monoterpenes