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

Abstract

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 (Martinez-Nunez, 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, <E(rot)> approximately 10 cm(-1)) are scattered from a 300 K perfluorinated liquid surface (PFPE) from a range of incident angles (theta(inc) = 0-60 degrees ). 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 (theta(inc) approximately 60 degrees ) reveal broad, lobular distributions peaking strongly in the forward subspecular direction as cos(n)(theta(scat) - theta') with n approximately 5.6(1.2) and theta' approximately 49(2) degrees .