Rate coefficients for the gas‐phase reactions of OH radicals with methylbutenols at 298 K

The relative‐rate method has been used to determine the rate coefficients for the reactions of OH radicals with three C 5 biogenic alcohols, 2‐methyl‐3‐buten‐2‐ol ( k 1 ), 3‐methyl‐3‐buten‐1‐ol ( k 2 ), and 3‐methyl‐2‐buten‐1‐ol ( k 3 ), in the gas phase. OH radicals were produced by the photolysis of CH 3 ONO in the presence of NO. Di‐ n ‐butyl ether and propene were used as the reference compounds. The absolute rate coefficients obtained with the two reference compounds agreed well with each other. The O 3 and O‐atom reactions with the target alcohols were confirmed to have a negligible contribution to their total losses by using two kinds of light sources with different relative rates of CH 3 ONO and NO 2 photolysis. The absolute rate coefficients were obtained as the weighted mean values for the two reference compound systems and were k 1 = (6.6 ± 0.5) × 10 −11 , k 2 = (9.7 ± 0.7) × 10 −11 , and k 3 = (1.5 ± 0.1) × 10 −10 cm 3 molecule −1 s −1 at 298 ± 2 K and 760 torr of air. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 379–385 2004