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

Abstract

AbstractExperimental 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.