Probing Conformational Heterogeneity at the Ionic Liquid-Vacuum Interface by Reactive-Atom Scattering

TY - JOUR

T1 - Probing Conformational Heterogeneity at the Ionic Liquid-Vacuum Interface by Reactive-Atom Scattering

AU - Smoll, Eric J.

AU - Purcell, Simon M.

AU - D'Andrea, Lucia

AU - Slattery, John Martin

AU - Bruce, Duncan Watson

AU - Costen, Matthew L.

AU - McKendrick, Kenneth G.

AU - Minton, Timothy K.

N1 - © 2018 American Chemical Society. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

PY - 2019/1/17

Y1 - 2019/1/17

N2 - The atomic-level description of liquid interfaces has lagged behind that ofsolid crystalline surfaces because existing experimental techniques have been limited in their capability to report molecular structure in a fluctuating liquid interfacial layer. We have moved toward a more detailed experimental description of the gas−liquid interface by studying the F-atom scattering dynamics on a common ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. When given contrast by deuterium labeling, the yield and dynamical behavior of reactively scattered HF isotopologues can resolve distinct signatures from the cation butyl, methyl, and ring groups, which help to quantify the relative populations of cation conformations at the liquid−vacuum interface. These results demonstrate the importance of molecular organization in driving sitespecific reactions at the extreme outer regions of the gas−liquid interface.

AB - The atomic-level description of liquid interfaces has lagged behind that ofsolid crystalline surfaces because existing experimental techniques have been limited in their capability to report molecular structure in a fluctuating liquid interfacial layer. We have moved toward a more detailed experimental description of the gas−liquid interface by studying the F-atom scattering dynamics on a common ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. When given contrast by deuterium labeling, the yield and dynamical behavior of reactively scattered HF isotopologues can resolve distinct signatures from the cation butyl, methyl, and ring groups, which help to quantify the relative populations of cation conformations at the liquid−vacuum interface. These results demonstrate the importance of molecular organization in driving sitespecific reactions at the extreme outer regions of the gas−liquid interface.

U2 - 10.1021/acs.jpclett.8b02920

DO - 10.1021/acs.jpclett.8b02920

M3 - Article

SN - 1948-7185

VL - 10

SP - 156

EP - 163

JO - JOURNAL OF PHYSICAL CHEMISTRY LETTERS

JF - JOURNAL OF PHYSICAL CHEMISTRY LETTERS

IS - 2

ER -