TY - JOUR
T1 - Infrared Spectrum of the Adduct 2-Chloro-2-hydroperoxybut-3-ene [(C2H3)CCl(CH3)OOH] of the Reaction between the Criegee Intermediate Methyl Vinyl Ketone Oxide [C2H3C(CH3)OO] and HCl
AU - Wang, Hao
AU - Lee, Yuan Pern
N1 - Publisher Copyright:
© 2024 The Authors. Published by American Chemical Society.
PY - 2024/10/10
Y1 - 2024/10/10
N2 - Methyl vinyl ketone oxide (MVKO, C2H3C(CH3)OO) is an important Criegee intermediate produced from ozonolysis of isoprene, which is the most abundant nonmethane hydrocarbon emitted into the atmosphere. Reactions between Criegee intermediate and hydrogen chloride (HCl) are important because of their large rate coefficients. In this work, we photolyzed a mixture of (Z)-(CH2I)HC═C(CH3)I/HCl/O2 at 248 nm to produce MVKO to carry out the reaction MVKO + HCl and recorded infrared spectra of transient species with a step-scan Fourier-transform infrared absorption spectrometer. Eleven bands near 1415, 1381, 1350, 1249, 1178, 1118, 1103, 1065, 978, 931, and 895 cm-1 were observed and assigned to the hydrogen-transferred adduct (C2H3)CCl(CH3)OOH (2-chloro-2-hydroperoxybut-3-ene, CHPB) according to the predicted IR spectrum using the B3LYP/aug-cc-pVTZ method; the conformation could not be definitively determined. According to calculations, most low-energy conformers can interconvert, and the most stable conformers anti-trans-CHPB and syn-trans-CHPB might have the major contributions. Four bands near 1423, 1360, 1220, and 1080 cm-1 were observed and tentatively assigned to the OH-decomposition products (C2H3)CCl(CH3)O (1-chloro-1-methyl-2-propenyloxy, CMP); both trans-CMP and cis-CMP might contribute. Unlike in the case of CH2OO + HCl and CH3CHOO + HCl, in which secondary reactions of the OH-decomposition products reacted readily with O2 to produce the dehydrated products HC(O)Cl and CH3C(O)Cl, respectively, the secondary reaction of CMP with O2 was not observed because there is no feasible H atom in CMP for O2 to abstract.
AB - Methyl vinyl ketone oxide (MVKO, C2H3C(CH3)OO) is an important Criegee intermediate produced from ozonolysis of isoprene, which is the most abundant nonmethane hydrocarbon emitted into the atmosphere. Reactions between Criegee intermediate and hydrogen chloride (HCl) are important because of their large rate coefficients. In this work, we photolyzed a mixture of (Z)-(CH2I)HC═C(CH3)I/HCl/O2 at 248 nm to produce MVKO to carry out the reaction MVKO + HCl and recorded infrared spectra of transient species with a step-scan Fourier-transform infrared absorption spectrometer. Eleven bands near 1415, 1381, 1350, 1249, 1178, 1118, 1103, 1065, 978, 931, and 895 cm-1 were observed and assigned to the hydrogen-transferred adduct (C2H3)CCl(CH3)OOH (2-chloro-2-hydroperoxybut-3-ene, CHPB) according to the predicted IR spectrum using the B3LYP/aug-cc-pVTZ method; the conformation could not be definitively determined. According to calculations, most low-energy conformers can interconvert, and the most stable conformers anti-trans-CHPB and syn-trans-CHPB might have the major contributions. Four bands near 1423, 1360, 1220, and 1080 cm-1 were observed and tentatively assigned to the OH-decomposition products (C2H3)CCl(CH3)O (1-chloro-1-methyl-2-propenyloxy, CMP); both trans-CMP and cis-CMP might contribute. Unlike in the case of CH2OO + HCl and CH3CHOO + HCl, in which secondary reactions of the OH-decomposition products reacted readily with O2 to produce the dehydrated products HC(O)Cl and CH3C(O)Cl, respectively, the secondary reaction of CMP with O2 was not observed because there is no feasible H atom in CMP for O2 to abstract.
UR - http://www.scopus.com/inward/record.url?scp=85205908794&partnerID=8YFLogxK
U2 - 10.1021/acs.jpca.4c04936
DO - 10.1021/acs.jpca.4c04936
M3 - Article
C2 - 39327098
AN - SCOPUS:85205908794
SN - 1089-5639
VL - 128
SP - 8690
EP - 8698
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 40
ER -