TOF spectra of the mass 113 product at selected LAB angles. The collision energy is 9.5 kcal/mol.
Newton diagram for the product of R4 (small circle, ) and the product of R5 (large circle, ) at a collision energy of 9.5 kcal/mol.
LAB-frame angular distributions of the mass 113 product at collision energies of 9.5 and 6.8 kcal/mol. The corresponding LAB angle of the center of mass is denoted as “CM.”
and used to simulate the TOF spectra and angular distributions for the mass 113 product of R4. Two distributions are used to fit the data at 6.8 kcal/mol: one for the forward direction and the other for the backward direction; for intermediate CM angles, an interpolated distribution is used.
TOF spectra of the mass 66 product at selected LAB angles. The collision energy is 9.5 kcal/mol.
and used to simulate the TOF spectra and angular distributions of the mass 66 product of R5 at representative collision energies. For collision energy of 6.8 kcal/mol or less, an isotropic angular distribution is used.
Upper panel: the relative signal ratio of R4/R5 as a function of collision energy. The horizontal error bar denotes the spread (at half maximum) of the collision energy. A linear function convoluted with the collision energy spread is shown as the solid line. Lower panel: the excitation function (relative reaction cross section as a function of collision energy) of R5 at low collision energies. Inset: representative TOF spectra of the mass 66 product at 1.6 kcal/mol collision energy; the LAB angle is .
Optimized structures of DMDS, VDW entrance well, transition states (TS1, TS2, and TS3), intermediates (INT1 and INT2), and . Selected bond distances (in angstrom) and angles (in degrees) are shown. See Table I for geometry parameters of INT2. The VDW, TS1, TS2, TS3, INT1, and INT2 structures are calculated with CASPT2 with an active space of (six electrons distributed in six orbitals). The DMDS and structures are calculated with B3LYP. Basis sets used are , , and .
Upper panel: selected bond distances along the minimum energy path. The first formed S–F bond is denoted as . Lower panel: the corresponding relative potential energy profile calculated with CASPT2. Solid circles: at optimized geometries along the reaction coordinate; open circles: at selected geometries in the unconstrained optimization processes to show the connectivity (see text). ; . Basis sets used are , , and .
Selected geometry parameters of INT2 obtained with various ab initio methods using basis sets: , , and . Units: angstrom and degrees.
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