Gas-Phase Reaction Kinetic Study of a Series of Methyl-Butenols with Ozone under Atmospherically Relevant Conditions
Ana-Maria Rusu Vasilache1, Claudiu Roman2,3, Iustinian G Bejan1,2
1Department of Chemistry, Faculty of Chemistry, "Alexandru Ioan Cuza" University of Iasi, 11 Carol I, 700506 Iasi, Romania.
Abstract:
Methyl-butenols are a category of oxygenated biogenic volatile organic compounds emitted by plants as part of their natural metabolic processes. This study examines the gas-phase reactions of ozone (O3) with five methyl-butenols (2-methyl-3-buten-2-ol, 3-methyl-2-buten-1-ol, 3-methyl-3-buten-1-ol, 2-methyl-3-buten-1-ol, and 3-methyl-3-buten-2-ol) under atmospheric conditions at a temperature of (298 ± 2) K and pressure of (1000 ± 10) mbar. The experimental values for the gas-phase reaction rate coefficients obtained in this study, by using the relative rate method, are as follows (in cm3 molecule-1 s-1): k(3-methyl-2-buten-1-ol + O3) = (311 ± 20) × 10-18, k(2-methyl-3-buten-2-ol + O3) = (9.55 ± 1.04) × 10-18, k(3-methyl-3-buten-1-ol + O3) = (7.29 ± 0.46) × 10-18, k(2-methyl-3-buten-1-ol + O3) = (4.25 ± 0.29) × 10-18, and k(3-methyl-3-buten-2-ol + O3) = (62.9 ± 6.8) × 10-18. The results are discussed in detail, with particular emphasis on the degree and type of substitutions of the double bond. The determined rate coefficient values are also compared to the available literature data and with estimates of the structure-activity relationship. Additionally, the atmospheric implications toward the tropospheric lifetime and photochemical ozone generation potential for the investigated compounds are provided, which highlight the atmospheric impact of methyl-butenol decomposition into the lower atmosphere.
Related Concept Videos
01:46Oxidative Cleavage of Alkenes: Ozonolysis
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
03:08Hydroboration-Oxidation of Alkenes
03:06Reaction Mechanisms
For instance, the decomposition of ozone appears to follow a mechanism with two steps:
02:50Catalysis
02:14SN2 Reaction: Kinetics
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
02:36Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...