Unexpected high yield of acrolein underlies the importance of the hydrogen-abstraction mechanism in photooxidation of allyl methyl sulfide (AMS).

CARDONA, ALEJANDRO L.; TERUEL, MARIANO; VENTURA, OSCAR N.

CHEMOSPHERE

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2024 vol. 354

0045-6535

his work explores theoretically the gas phase oxidation of allyl methyl sulfide (AMS, H2C––CHCH2SCH3)initiated by •OH radicals, focusing on the H-abstraction pathway at the M06-2X-D3/aug-cc-pVTZ and MN15/aug-cc-pVTZ levels of theory (m06Tz and mn15Tz). The formation of a prereactive complex (PRC) is involvedin H-abstraction processes with two potential directions of approach for the OH radical, denoted as “α” and “β”.The PRCs, demonstrate increased reactivity, primarily due to the interaction between the sulfur atoms and thehydroxyl hydrogen. A scheme for the H-abstraction mechanism that supports the experimentally identifiedproducts and predicts the formation of some S-containing low volatility products is proposed. The comparison ofthe potential energy surface (PES) between the double bond addition and H-abstraction paths in the AMS molecule shows that at the m06Tz level of theory, the H-abstraction on C3 and the addition to C1 have nearly the same profile of energy, while