Formation threshold structures of some [C5H7O]+ ions: use of general schemes for estimation of heats of formation of gas-phase organic ions

1985 ◽  
Vol 63 (4) ◽  
pp. 833-835 ◽  
Author(s):  
Mehrshid Alai ◽  
Giorgio G. Attardo ◽  
Robin T. B. Rye
Keyword(s):  
Gas Phase ◽  
Heat Of Formation ◽  
Molecular Ions ◽  
Thermochemical Data ◽  
Mesityl Oxide ◽  
Methyl Radical ◽  
Organic Ions ◽  
Gas Phase Ions ◽  
Structure Assignment ◽  
Methyl Radical Loss

Recently published correlations between heat of formation and structure of gas-phase ions have been used to assign formation threshold structures to [C5H7O]+ ions produced by methyl radical loss from molecular ions of mesityl oxide, 5-hexene-2-one, 3-methylcyclopentanone, and 2-cyclohexenol. An unambiguous structure assignment has been made for the [C5H7O]+ daughter ion from mesityl oxide. For the three other precursors two common formation-threshold structures consistent with the thermochemical data are proposed.

The laser spectroscopy of cool, cold, and very cold molecular ions

1982 ◽  
Vol 307 (1500) ◽  
pp. 617-631 ◽  
Keyword(s):  
Gas Phase ◽  
Elevated Temperatures ◽  
Laser Induced Fluorescence ◽  
Molecular Ions ◽  
Organic Ions ◽  
Free Jet ◽  
Spectroscopic Information ◽  
Jahn Teller ◽  
High Concentrations ◽  
Expansion Cooling

Molecular ions have long presented a challenge to spectroscopists. Because of the extreme difficulty in generating molecular ions in high concentrations, sensitivity limitations have restricted work in this field. The technique of laser-induced fluorescence (l.i.f.) has provided us with a means to partially overcome this limitation. L.i.f. spectra of small molecular ions, e.g. N 2 +, CO+ and CO 2 +, show Doppler-limited resolution. Besides their spectroscopic information content, such spectra also serve as quantum-state selective ion detectors, by which dynamical processes involving such ions can be followed. L.i.f. spectra have also been recorded for larger organic ions, e.g. olefinic, acetylenic and benzenoid cations. The large molecular ions’ spectral congestion, caused by the large number of levels populated at room or elevated temperatures, can severely limit the resolution and interpretability of the spectra. As a means of surmounting this problem, we have studied many of the cations at reduced temperatures. The techniques employed include liquid N 2 and free jet expansion cooling in the gas phase, and isolation in solid Ne matrices. The combination of these different spectra lead to a wealth of information about electronic structure, vibrational frequencies, Jahn-Teller effects, etc., in organic molecular ions.

Radiation less transitions in gas phase molecular ions

1980 ◽  
Vol 77 ◽  
pp. 705-718 ◽  
Author(s):  
Sydney Leach ◽  
Gérald Dujardin ◽  
Guy Taieb
Keyword(s):  
Gas Phase ◽  
Molecular Ions

Linear free energy relationships in CN bond dissociations in molecular ions of 4-substitutedN-(2-furylmethyl)anilines in the gas phase

2007 ◽  
Vol 42 (11) ◽  
pp. 1496-1503 ◽  
Author(s):  
Eduardo A. Solano Espinoza ◽  
Elena Stashenko ◽  
Jairo Martínez ◽  
Uriel Mora ◽  
Vladimir Kouznetsov
Keyword(s):  
Free Energy ◽  
Gas Phase ◽  
Molecular Ions ◽  
Linear Free Energy Relationships ◽  
Linear Free Energy ◽  
Energy Relationships

Ab initio calculation of the thermochemical data on the H3O++H2O=H5O+2 gas‐phase clustering

1984 ◽  
Vol 80 (4) ◽  
pp. 1576-1578 ◽  
Author(s):  
Shinichi Yamabe ◽  
Tsutomu Minato ◽  
Kimihiko Hirao
Keyword(s):  
Ab Initio ◽  
Gas Phase ◽  
Ab Initio Calculation ◽  
Thermochemical Data

Infrared fluorescence relaxation of photoexcited gas‐phase ions by chopped‐laser two‐photon dissociation

1987 ◽  
Vol 86 (4) ◽  
pp. 2081-2086 ◽  
Author(s):  
Robert C. Dunbar ◽  
Jyh Horung Chen ◽  
Hun Young So ◽  
Bruce Asamoto
Keyword(s):  
Gas Phase ◽  
Two Photon ◽  
Gas Phase Ions
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