An experimental and theoretical study on the kinetics of the reaction between 4-hydroxy-3-hexanone CH3CH2C(O)CH(OH)CH2CH3 and OH radicals

International audienceExperimental and theoretical rate coefficients are determined for the first time for the reaction of 4-hydroxy-3-hexanone (CH3CH2C(O)CH(OH)CH2CH3) with OH radicals as a function of temperature. Experimental studies were carried out using two techniques. Absolute rate coefficients were measured using a cryogenically cooled cell coupled to the pulsed laser photolysis-laser-induced fluorescence technique with temperature and pressure ranges of 280-365 K and 5-80 Torr, respectively. Relative values of the studied reaction were measured under atmospheric pressure in the range of 298-354 K by using a simulation chamber coupled to a FT-IR spectrometer. In addition, the reaction of 4H3H with OH radicals was studied theoretically by using the density functional theory method over the range of 278-350 K. Results show that H-atom abstraction occurs more favorably from the C-H bound adjacent to the hydroxyl group with small barrier height. Theoretical rate coefficients are in good agreement with the experimental data. A slight negative temperature dependence was observed in both theoretical and experimental works. Overall, the results are deliberated in terms of structure-reactivity relationship and atmospheric implications