TY - JOUR
T1 - Dissociation dynamics of propargyl chloride molecular ion near the reaction threshold
T2 - Manifestation of quantum mechanical tunneling
AU - Won, Dong Shin
AU - Choe, Joong Chul
AU - Kim, Myung Soo
PY - 2000
Y1 - 2000
N2 - The Cl loss from the propargyl chloride molecular ion has been investigated using mass-analyzed ion kinetic energy spectrometry (MIKES). The kinetic energy release distribution in the unimolecular dissociation has been determined. The potential energy surface for the mechanistic pathway has been calculated at the B3LYP/6-311G density functional theory level. The calculated potential energy surface suggested that the threshold dissociation of the propargyl chloride molecular ion produces the C3H+3 ion, only with the cyclopropenium structure, and with the release of a large amount of kinetic energy. This is in agreement with experimental results. Also, calculation of the rate constants with statistical rate models predicted that the reaction observed on a microsecond time scale occurs via tunneling through the rate-determining isomerization barrier for H-atom transfer. It has been found that a broad lifetime distribution is a manifestation of quantum mechanical tunneling of a precursor prepared under thermal conditions. Reinterpretation of previous photoelectron-photoion coincidence results taking into account the tunneling effect necessitated raising the critical energy to 0.64 eV from the energy of 0.34 eV reported previously. Copyright (C) 2000 John Wiley and Sons, Ltd.
AB - The Cl loss from the propargyl chloride molecular ion has been investigated using mass-analyzed ion kinetic energy spectrometry (MIKES). The kinetic energy release distribution in the unimolecular dissociation has been determined. The potential energy surface for the mechanistic pathway has been calculated at the B3LYP/6-311G density functional theory level. The calculated potential energy surface suggested that the threshold dissociation of the propargyl chloride molecular ion produces the C3H+3 ion, only with the cyclopropenium structure, and with the release of a large amount of kinetic energy. This is in agreement with experimental results. Also, calculation of the rate constants with statistical rate models predicted that the reaction observed on a microsecond time scale occurs via tunneling through the rate-determining isomerization barrier for H-atom transfer. It has been found that a broad lifetime distribution is a manifestation of quantum mechanical tunneling of a precursor prepared under thermal conditions. Reinterpretation of previous photoelectron-photoion coincidence results taking into account the tunneling effect necessitated raising the critical energy to 0.64 eV from the energy of 0.34 eV reported previously. Copyright (C) 2000 John Wiley and Sons, Ltd.
UR - http://www.scopus.com/inward/record.url?scp=0011578210&partnerID=8YFLogxK
U2 - 10.1002/1097-0231(20000715)14:13<1110::AID-RCM995>3.0.CO;2-J
DO - 10.1002/1097-0231(20000715)14:13<1110::AID-RCM995>3.0.CO;2-J
M3 - Article
AN - SCOPUS:0011578210
SN - 0951-4198
VL - 14
SP - 1110
EP - 1115
JO - Rapid Communications in Mass Spectrometry
JF - Rapid Communications in Mass Spectrometry
IS - 13
ER -