1 research outputs found
OH-Stretching Overtone Induced Dynamics in HSO<sub>3</sub>F from Reactive Molecular Dynamics Simulations
The OH-stretch induced dynamics in
fluorosulfonic acid (HSO<sub>3</sub>F) is characterized from a statistically
significant number
of trajectories using multisurface adiabatic reactive molecular dynamics
(MS-ARMD) simulations. The global reactive potential energy surface,
which describes H-transfer and HF-elimination, is parametrized at
the MP2/6-311G++(2p,2d) level of theory with an accuracy of better
than 1 kcal/mol. Excitation along the OH-local mode leads to H-transfer
dynamics but elimination of HF is only observed for excitations with
ν ≥ 6 for 1 out of 5000 trajectories. This finding differs
fundamentally from the situation for vibrationally induced photodissociation
of H<sub>2</sub>SO<sub>4</sub> and HSO<sub>3</sub>Cl, for which, even
with excitations of 4 quanta along the OH-stretch mode, elimination
of H<sub>2</sub>O and HCl, respectively, is readily observed on the
subnanosecond time scale. RRKM rates for HX-elimination in HSO<sub>3</sub>X (X = F, Cl) only differ by a factor of 5. The findings from
the reactive molecular dynamics simulations together with the RRKM
results thus indicate that the origin for a closed HF-production channel
is dynamical. This is also consistent with experimental findings for
hydrofluoroethanes in shock tubes, which found pronounced non-RRKM
behavior