@article{13118,
  author = {Mikhail Ryazanov and David Nesbitt},
  title = {Non-equilibrium dynamics at the gas-liquid interface: State-resolved studies of NO evaporation from a benzyl-alcohol liquid microjet},
  abstract = {<p>ConspectusWe often teach or are taught in our freshman courses that there are three phases of matter─gas, liquid and solid─where the ordering reflects increasing complexity and strength of interaction between the molecular constituents. But arguably there is also a fascinating additional "phase" of matter associated with the microscopically thin interface (&lt;10 molecules thick)&nbsp;<i>between</i>&nbsp;the gas and liquid, which is still poorly understood and yet plays a crucial role in fields ranging from chemistry of the marine boundary layer and atmospheric chemistry of aerosols to the passage of O<sub>2</sub>&nbsp;and CO<sub>2</sub>&nbsp;through alveolar sacs in our lungs. The work in this Account provides insights into three challenging new directions for the field, each embracing a rovibronically quantum-state-resolved perspective. Specifically, we exploit the powerful tools of chemical physics and laser spectroscopy to pose two fundamental questions. (i) At the microscopic level, do molecules in all internal quantum-states (e.g., vibrational, rotational, electronic) colliding with the interface "stick" with unit probability? (ii) Can reactive, scattering, and/or evaporating molecules at the gas-liquid interface avoid collisions with other species and thereby be observed in a truly "nascent" collision-free distribution of internal degrees of freedom? To help address these questions, we present studies in three different areas: (i) reactive scattering dynamics of F atoms with wetted-wheel gas-liquid interfaces, (ii) inelastic scattering of HCl from self-assembled monolayers (SAMs) via resonance-enhanced photoionization (REMPI)/velocity map imaging (VMI) methods, and (iii) quantum-state-resolved evaporation dynamics of NO at the gas-water interface. As a recurring theme, we find that molecular projectiles reactively, inelastically, or evaporatively scatter from the gas-liquid interface into internal quantum-state distributions&nbsp;<i>substantially out of equilibrium</i>&nbsp;with respect to the bulk liquid temperatures (<i>T</i><sub>S</sub>). By detailed balance considerations, the data unambiguously indicate that even simple molecules exhibit rovibronic state dependences to how they "stick" to and eventually solvate into the gas-liquid interface. Such results serve to underscore the importance of&nbsp;<i>quantum mechanics and nonequilibrium thermodynamics</i>&nbsp;in energy transfer and chemical reactions at the gas-liquid interface. This nonequilibrium behavior may well make this rapidly emergent field of chemical dynamics at gas-liquid interfaces more complicated but even more interesting targets for further experimental/theoretical exploration.</p>
},
  year = {2023},
  journal = {Journal of Chemical Physics},
  volume = {158},
  pages = {144703},
  month = {2023-04},
  doi = {10.1021/acs.accounts.2c00823},
}