Test of a chemical timing method for measuring absolute vibrational relaxation rate constants for S1 p-difluorobenzene.

A chemical timing (CT) method for measuring absolute rate constants for collisional vibrational relaxation has been tested for the 5(1) state of S(1) p-difluorobenzene (pDFB) where an alternative method exists to provide benchmark values. The CT method was originally developed to treat vibrational energy transfer (VET) in large molecules excited to high vibrational levels where the intramolecular vibrational redistribution (IVR) resulting from large vibrational state densities completely eliminates vibrational structure in the emission spectrum. Here we apply the same method to a low-lying state (5(1) with epsilon(vib) = 818 cm(-1)) located in the low-density region of the vibrational manifold where IVR plays no role.

Dynamics of energy transfer in collisions of O(3P) atoms with a 1-decanethiol self-assembled monolayer surface.

Chemical dynamics simulations are reported of energy transfer in collisions of O(3P) atoms with a 300 K 1-decanethiol self-assembled monolayer (H-SAM) surface. The simulations are performed with a nonreactive potential energy surface, developed from PMP2/aug-cc-pVTZ calculations of the O(3P) + H-SAM intermolecular potential, and the simulation results represent the energy transfer dynamics in the absence of O(3P) reaction. Collisions energies E(i) of 0.