Rate and mechanism of the reactions of OH and Cl with 2-methyl-3-buten-2-ol

An environmental chamber/Fourier transform infrared system was used to determine the rate coefficient k₁ for the gas-phase reaction of OH with 2-methyl-3-buten-2-ol (MBO, (CH₃)₂C(OH)CH=CH₂), relative to the rate of its reaction with ethylene (k₂) and propylene (k₃). Experiments performed at 295 ± 1 K, in 700 torr total pressure of air, gave k₁ = (6.9 ± 1.0) × 10^-11 cm³ molecule^-1 s^-1. At 295 ± 1 K, the reaction of OH with MBO yielded, on a per mole basis, (52 ± 5)% acetone, (50 ± 5)% glycolaldehyde, and (35 ± 4)% formaldehyde. The production of acetone from the oxidation of MBO may be of significance globally. The kinetics and mechanism of the reaction of chlorine atoms with MBO (k₁₅) have also been studied at 700 torr total pressure of air and 295 ± 1 K. The rate coefficient was determined using a relative rate technique, with ethane (k₁₆), ethylene (k₁₇), and cyclohexane (k₁₈) as reference compounds. The value of k₁₅ was found to be (3.3 ± 0.4) × 10^-10 cm³ molecule^-1 s^-1 at 295 K. The major carbon-containing products obtained in the Cl-atom oxidation of MBO were acetone (47 ± 5)%, chloroacetaldehyde (53 ± 5)%, HCOCl (<11%), and formaldehyde (6 ± 2)%.