Theoretical Insight into the Reaction Mechanism and Kinetics for the Criegee Intermediate of anti-PhCHOO with SO2

Abstract

<jats:p>In this study, the density functional theory (DFT) and CCSD(T) method have been performed to gain insight into the possible products and detailed reaction mechanism of the Criegee intermediate (CI) of anti-PhCHOO with SO2 for the first time. The potential energy surfaces (PESs) have been depicted at the UCCSD(T)/6-311++G(d,p)//UB3LYP/6-311++G(d,p) levels of theory with ZPE correction. Two different five-membered ring adducts, viz., endo PhCHOOS(O)O (IM1) and exo PhCHOOS(O)O (IM2) have been found in the entrance of reaction channels. Both direct and indirect reaction pathways from IM1 and IM2 have been considered for the title reaction. Our calculations show that the formation of PhCHO+SO3 (P1) via indirect reaction pathways from IM1 is predominant in all the pathways, and the production of P1 via direct dissociation pathway of IM1 and indirect reaction pathways of IM2 cannot be neglected. Moreover, PhCOOH+SO2 (P2) initiated from IM2 is identified as the minor product. According to the kinetic calculation, the total rate constant for the anti-PhCHOO+SO2 reaction is estimated to be 6.98 × 10−10 cm3·molecule−1·s−1 at 298 K.</jats:p>

Bimolecular Reaction of Methyl-Ethyl-Substituted Criegee Intermediate with SO2

“…There have been numerous prior theoretical studies on the reactions of sCIs with SO 2 , ,,− most of which have primarily focused on the reactions of CH 2 OO and/or (CH 3 ) 2 COO, although some have also considered the reaction with larger CIs. ,, The potential energy surfaces were generally explored with CCSD­(T)-based evaluations at stationary points or minimum energy paths determined by density functional theory. These prior studies uniformly conclude that the initial addition process between the sCI and SO 2 is strongly attractive.…”

Unveiling the Mechanisms of Hydrolytic Ring-Opening Polymerization of Caprolactam and Amino-Assisted Ring Opening of Cyclic Dimers: A DFT Study

“…However, there is no report on the inhibition mechanism of amino groups on cyclic dimers. As everyone knows, experimental techniques can rarely provide detailed information of reaction dynamics, while theoretical simulation is the reliable and effective method to explore the reaction mechanism. , All these questions mentioned above stimulate our interest in the title reaction and need to be answered by the theoretical calculations. We hope that our theoretical results can explain the experimental observations and provide some useful information for similar or new reactions.…”