Toward Three-Dimensional Quantum State-Resolved Collision Dynamics at the Gas_Liquid Interface: Theoretical Investigation of Incident Angle

摘要

Quantum state-resolved energy transfer dynamics at the gas-liquid interface are explored through a comparison of classical molecular dynamics (MD) simulations and previously reported experimental studies (Perkins, B. G.; et al. J. Phys. Chem. A 2008, 112, 9234). Theoretically, large scale MD trajectory calculations have been performed for collisions of CO_2 with a model fluorinated self-assembled monolayer surface (F-SAMs), based on an explicit atom-atom interaction potential obtained from earlier theoretical studies (Martínez-Nú_ez, E.; et al. J. Phys. Chem. C 2007, 111, 354). Initial conditions for the simulations match those in the experimental studies where high-energy jet-cooled CO_2 molecules (E_(inc) = 10.6(8) kcal/mol, ～ 10 cm~(-1)) are scattered from a 300 K perfluorinated liquid surface (PFPE) from a range of incident angles (θ_(inc) = 0-60°). Nascent CO_2 rotational distributions prove to be remarkably well characterized by a simple two-temperature trapping-desorption (TD) and impulsive scattering (IS) model with nearly quantitative agreement between experimental and theoretical column integrated densities. Furthermore, three-dimensional (3D) quantum state resolved flux maps for glancing incident angles (0_(inc)～ 60°) reveal broad, lobular distributions peaking strongly in the forward subspecular direction as cos~n(θ_(scat) - θ') with n ≈ 5.6(1.2) and θ'≈ 49(2)°.