Atmospheric degradation, mechanism and kinetics of ethyl vinyl ketone (CH2=CHCOCH2CH3) initiated by Cl atom: an insight from DFT study

• Published in: Molecular physics Vol. 120; no. 13
• Main Authors: Yadav, Ajay Kumar, Mishra, Bhupesh Kumar, Singh, Ashutosh, Gour, Nand Kishor
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 03.07.2022; Taylor & Francis Ltd
• Subjects: Channels; Density functional theory; EVK; H-abstractions; Ketones; Kinetics; lifetime; M06-2X; Mathematical analysis; Potential energy; rate constant; Rate constants
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268976.2022.2100835

The mechanism and kinetics of the H-abstractions of ethylvinylketone (CH 2 =CHCOCH 2 CH 3 ) with Cl atom have been carried out using density functional theory (DFT). The electronic structures and frequencies of reaction species are carried out at M06-2X/6-31+G(d,p) level. The energy calculation is performed for optimised species at the same functionality but using a 6-311++G(d,p) basis set. We characterised transition states (TSs) in each H-abstraction channel and explored reaction species along with TS involved in CH 2 =CHCOCH 2 CH 3 +Cl reaction on the potential energy diagram. Among the various H-abstraction channels, H-abstraction from the methylene group (-CH 2 -) of CH 2 =CHCOCH 2 CH 3 is found to be a more dominant reaction channel which is further confirmed by thermochemical analysis. The rate constants of all H-abstraction reaction channels and overall rate constant are calculated using canonical transition state theory (TST) within the temperature range of 200-400 K. The value of the overall rate constant at 298.15 K and 1atm pressure is found to be 0.94 × 10 −10 cm 3 mol −1 s −1 , which is in close with the experimental reported rate constant value, i.e. (2.91 ± 1.10) × 10 −10 cm 3 mol −1 s −1 . The percentage branching ratios of each H-abstraction reaction channel, as well as the lifetime of the titled compound, are also reported herein.