TY - JOUR AU - Timothy Large AB - Quantum-state-resolved collisional energy transfer of jet-cooled carbonyl sulfide (OCS) at the gas–liquid interface (Einc = 2.2(4) kcal/mol) has been explored with a powerful combination of molecular beam scattering and high-resolution direct absorption IR spectroscopy, which has permitted the first characterization of rotational, vibrational, and transverse Doppler excitation/accommodation dynamics on a liquid for a polyatomic projectile. The results are consistent with the complete rotational and transverse translational equilibration of the incident OCS (Trot,trans ≈ 10 K) with the surface for a variety of liquids (perfluorinated polyether (PFPE), squalene, and glycerol) and liquid temperatures (TS = 263–303 K). In dramatic contrast, however, vibrational populations in the ground (0000), v2 OCS bend (0110), and ν1 CS stretch (1000) modes for the scattered OCS species remain far out of equilibrium with the liquid surface, indeed exhibiting adiabatic, spectator-like behavior and remaining identical (within experimental uncertainty) to vibrational temperatures observed in the incident OCS molecular beam. This spectator-like behavior for vibrational scattering clearly suggests that polyatomic vibrational coordinates must be treated separately from the other degrees of freedom, at least for low energies explored herein characteristic of the thermal desorption TD pathway. Such vibrationally decoupled behavior at energies and repulsive wall potentials sampled by the TD channel is shown to be in excellent qualitative agreement with expectations from high-level ab initio calculations and well-known Landau–Teller/Rapp vibrational energy-transfer models. BT - The Journal of Physical Chemistry C DA - 2021/10 DO - 10.1021/acs.jpcc.1c05993 IS - 41 N2 - Quantum-state-resolved collisional energy transfer of jet-cooled carbonyl sulfide (OCS) at the gas–liquid interface (Einc = 2.2(4) kcal/mol) has been explored with a powerful combination of molecular beam scattering and high-resolution direct absorption IR spectroscopy, which has permitted the first characterization of rotational, vibrational, and transverse Doppler excitation/accommodation dynamics on a liquid for a polyatomic projectile. The results are consistent with the complete rotational and transverse translational equilibration of the incident OCS (Trot,trans ≈ 10 K) with the surface for a variety of liquids (perfluorinated polyether (PFPE), squalene, and glycerol) and liquid temperatures (TS = 263–303 K). In dramatic contrast, however, vibrational populations in the ground (0000), v2 OCS bend (0110), and ν1 CS stretch (1000) modes for the scattered OCS species remain far out of equilibrium with the liquid surface, indeed exhibiting adiabatic, spectator-like behavior and remaining identical (within experimental uncertainty) to vibrational temperatures observed in the incident OCS molecular beam. This spectator-like behavior for vibrational scattering clearly suggests that polyatomic vibrational coordinates must be treated separately from the other degrees of freedom, at least for low energies explored herein characteristic of the thermal desorption TD pathway. Such vibrationally decoupled behavior at energies and repulsive wall potentials sampled by the TD channel is shown to be in excellent qualitative agreement with expectations from high-level ab initio calculations and well-known Landau–Teller/Rapp vibrational energy-transfer models. PY - 2021 SN - 1932-7447 SP - 22786 EP - 22796 EP - T2 - The Journal of Physical Chemistry C TI - State-Resolved Studies of OCS Scattering at the Gas−Liquid Interface: Tests of Landau−Teller/Rapp Theory for Rotational vs Vibrational Energy Transfer UR - https://doi.org/10.1021/acs.jpcc.1c05993 VL - 125 ER -