Tunable wavelength soft photoionization of ionic liquid vapors

Journal Article · Wed Nov 11 00:00:00 EST 2009 · Journal of Physical Chemistry A

OSTI ID:983009

Strasser, Daniel; Goulay, Fabien; Belau, Leonid; Kostko, Oleg; Koh, Christine; Chambreau, Steven D; Vaghjiani, Ghanshyam L; Ahmed, Musahid; Leone, Stephen R

Combined data of photoelectron spectra and photoionization efficiency curves in the near threshold ionization region of isolated ion-pairs from [emim][Tf2N], [emim][Pf2N]and [dmpim][Tf2N]ionic liquid vapors reveal small shifts in the ionization energies of ion-pair systems due to cation and anion substitutions. Shifts towards higher binding energy following anion substitution are attributed to increased electronegativity of the anion itself, while shifts towards lower binding energies following cation substitution are attributed to an increase in the cation-anion distance that causes a lower Coulombic binding potential. The predominant ionization mechanism in the near threshold photon energy region is identified as dissociative ionization, involving dissociation of the ion-pair and the production of intact cations as the positively charged products.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: Chemical Sciences Division
• DOE Contract Number: DE-AC02-05CH11231
• OSTI ID: 983009
• Report Number(s): LBNL-3160E; TRN: US1004344
• Journal Information: Journal of Physical Chemistry A, Journal Name: Journal of Physical Chemistry A
• Country of Publication: United States
• Language: English

Related Subjects

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37
ANIONS
BINDING ENERGY
CATIONS
DISSOCIATION
EFFICIENCY
ELECTRONEGATIVITY
ION PAIRS
IONIZATION
PHOTOIONIZATION
PHOTONS
PRODUCTION
SPECTRA
WAVELENGTHS
gas phase
ionic liquids
ionization energy
photoionization efficiency
photoelectron spectrum
synchrotron
high order harmonics