TY - JOUR
T1 - A direct dynamics trajectory study of F- + CH3OOH reactive collisions reveals a major non-IRC reaction path
AU - López, José G.
AU - Vayner, Grigoriy
AU - Lourderaj, Upakarasamy
AU - Addepalli, Srirangam V.
AU - Kato, Shuji
AU - DeJong, Wibe A.
AU - Windus, Theresa L.
AU - Hase, William L.
PY - 2007/8/15
Y1 - 2007/8/15
N2 - A direct dynamics simulation at the B3LYP/6-311+G(d,p) level of theory was used to study the F- + CH3OOH reaction dynamics. The simulations are in excellent agreement with a previous experimental study (J. Am. Chem. Soc. 2002, 124, 3196). Two product channels, HF + CH2O + OH- and HF + CH3OO-, are observed. The former dominates and occurs via an ECO2 mechanism in which F- attacks the CH3-group, abstracting a proton. Concertedly, a carbon-oxygen double bond is formed and OH- is eliminated. Somewhat surprisingly this is not the reaction path, predicted by the intrinsic reaction coordinate (IRC), which leads to a deep potential energy minimum for the CH 2(OH)2⋯F- complex followed by dissociation to HF + CH2(OH)O-. None of the direct dynamics trajectories followed this path, which has an energy release of -63 kcal/mol and is considerably more exothermic than the ECO2 path whose energy release is -27 kcal/mol. Other product channels not observed, and which have a lower energy than that for the ECO2 path, are F- + CO + H2 + H2O (-43 kcal/mol), F- + CH 2O + H2O (-51 kcal/mol), and F- + CH 2(OH)2 (-60 kcal/mol). Formation of the CH 3OOH⋯F- complex, with randomization of its internal energy, is important, and this complex dissociates via the ECO2 mechanism. Trajectories which form HF + CH3OO- are nonstatistical events and, for the 4 ps direct dynamics simulation, are not mediated by the CH3OOH⋯F- complex. Dissociation of this complex to form HF + CH3OO- may occur on longer time scales.
AB - A direct dynamics simulation at the B3LYP/6-311+G(d,p) level of theory was used to study the F- + CH3OOH reaction dynamics. The simulations are in excellent agreement with a previous experimental study (J. Am. Chem. Soc. 2002, 124, 3196). Two product channels, HF + CH2O + OH- and HF + CH3OO-, are observed. The former dominates and occurs via an ECO2 mechanism in which F- attacks the CH3-group, abstracting a proton. Concertedly, a carbon-oxygen double bond is formed and OH- is eliminated. Somewhat surprisingly this is not the reaction path, predicted by the intrinsic reaction coordinate (IRC), which leads to a deep potential energy minimum for the CH 2(OH)2⋯F- complex followed by dissociation to HF + CH2(OH)O-. None of the direct dynamics trajectories followed this path, which has an energy release of -63 kcal/mol and is considerably more exothermic than the ECO2 path whose energy release is -27 kcal/mol. Other product channels not observed, and which have a lower energy than that for the ECO2 path, are F- + CO + H2 + H2O (-43 kcal/mol), F- + CH 2O + H2O (-51 kcal/mol), and F- + CH 2(OH)2 (-60 kcal/mol). Formation of the CH 3OOH⋯F- complex, with randomization of its internal energy, is important, and this complex dissociates via the ECO2 mechanism. Trajectories which form HF + CH3OO- are nonstatistical events and, for the 4 ps direct dynamics simulation, are not mediated by the CH3OOH⋯F- complex. Dissociation of this complex to form HF + CH3OO- may occur on longer time scales.
UR - http://www.scopus.com/inward/record.url?scp=34547893403&partnerID=8YFLogxK
U2 - 10.1021/ja0717360
DO - 10.1021/ja0717360
M3 - Article
C2 - 17658801
AN - SCOPUS:34547893403
VL - 129
SP - 9976
EP - 9985
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 32
ER -