The fluoroformate ion, FCO2−. An ion cyclotron resonance study of the gas phase Lewis acidity of carbon dioxide and related isoelectronic species

1978 ◽  
Vol 56 (8) ◽  
pp. 1069-1074 ◽  
Author(s):  
Terrance Brian McMahon ◽  
Colleen Joan Northcott
Keyword(s):  
Carbon Dioxide ◽  
Gas Phase ◽  
Lewis Acidity ◽  
Ion Cyclotron Resonance ◽  
Dissociation Energies ◽  
Ion Molecule Reactions ◽  
Gas Phase Acidity ◽  
Gas Phase Ion ◽  
Carbonyl Fluoride

The gas phase ion molecule reactions of a number of potential fluoride donors with carbon dioxide and carbonyl fluoride have been studied. By determination of preferential directions of fluoride transfer the fluoride affinities of carbon dioxide and carbonyl fluoride have been bracketed and found to be 33 ± 3 kcal/mol and 35 + 3 kcal/mol respectively. In addition, from gas phase acidity studies of acetyl fluoride and 2-fluoropropene the fluoride affinities of ketene and allene have been calculated to be 38 ± 2 kcal/mol and 15 ± 2 kcal/mol respectively. The order of fluoride affinities (Lewis acidities) of carbon dioxide, ketene, and allene have been examined and explained in terms of the electron affinities of the F—C(A)(B) species (A,B=O,CH2) and the C—F bond dissociation energies. These quantities have been estimated and the latter interpreted on the basis of the π bond energies of the three compounds.

scholarly journals Bimolecular production of proton bound dimers in the gas phase. A low pressure ion cyclotron resonance technique for examination of solvent exchange equilibria and determination of single molecule solvation energetics

1982 ◽  
Vol 60 (4) ◽  
pp. 542-544 ◽  
Author(s):  
J. W. Larson ◽  
R. L. Clair ◽  
T. B. McMahon
Keyword(s):  
Gas Phase ◽  
Single Molecule ◽  
Cyclotron Resonance ◽  
Ion Cyclotron Resonance ◽  
Solvent Exchange ◽  
Ion Molecule Reactions ◽  
Ion Cyclotron ◽  
Gas Phase Ion ◽  
Low Pressures

A scheme is presented whereby sequences of fast bimolecular gas phase ion molecule reactions in mixtures containing (CHF2)2O may be used to generate proton bound dimer species at low pressures in an ion cyclotron resonance spectrometer. Using competitive solvent switching reactions it is demonstrated that solvent exchange equilibria may be readily established and from the thermochemical data derived from such equilibria accurate relative single molecule solvation energetics obtained.

Thermodynamic control in the reactions of gas phase anions. An abinitio and ion cyclotron resonance study of the reactions of anions with diborane

1985 ◽  
Vol 63 (2) ◽  
pp. 281-287 ◽  
Author(s):  
O. Elsenstein ◽  
M. Kayser ◽  
M. Roy ◽  
T. B. McMahon
Keyword(s):  
Gas Phase ◽  
Cyclotron Resonance ◽  
Reaction Pathway ◽  
Basis Set ◽  
Resonance Spectroscopy ◽  
Ion Cyclotron Resonance ◽  
Ion Molecule Reactions ◽  
Ion Cyclotron ◽  
Reaction Channels ◽  
Gas Phase Ion

The gas phase ion molecule reactions of a number of anions, X−, with diborane, B2H6 have been investigated using ion cyclotron resonance spectroscopy. Two distinct reaction channels are observed in addition to simple proton transfer. The first of these is production of BH4− and BH2X while the second is formation of BH3X− and BH3. In order to determine the importance of thermodynamic factors in the course of reaction abinitio calculations have been carried out on the species involved to obtain the relative stabilities of the two possible pairs of products. The 4-31 +G basis set incorporating additional flat s and p functions has been used since this basis set has been demonstrated to give the most accurate description of anions to date. The results obtained indicate that the thermochemical factors are instrumental in determining the reaction pathway.

scholarly journals The Determination of Electron Abundances in Interstellar Clouds

1980 ◽  
Vol 87 ◽  
pp. 339-340
Author(s):  
Alwyn Wootten ◽  
Ronald Snell ◽  
A. E. Glassgold
Keyword(s):  
Gas Phase ◽  
Molecular Clouds ◽  
Cosmic Ray ◽  
Ionization Rate ◽  
Interstellar Clouds ◽  
Ion Molecule Reactions ◽  
Upper Limits ◽  
Gas Phase Ion ◽  
Existing Data

A new method for estimating electron fractions in shielded molecular clouds is proposed on the basis of gas phase ion-molecule reactions which involves measuring the quantity . Applied to existing data, it yields upper limits to Xe in the range from 10−8 to 10−7 for a variety of clouds, warm as well as cool. An upper bound to the cosmic ray ionization rate is also obtained.

A gas phase study of the regioselective BH4− reduction of some 2-substituted maleic anhydrides

1988 ◽  
Vol 66 (10) ◽  
pp. 2587-2594 ◽  
Author(s):  
Hans van der Wel ◽  
Nico M. M. Nibbering ◽  
Margaret M. Kayser
Keyword(s):  
Carbon Atom ◽  
Gas Phase ◽  
Ion Cyclotron Resonance ◽  
Ion Transfer ◽  
Hydride Ion ◽  
Ion Molecule Reactions ◽  
Phase Study ◽  
Olefinic Double Bond ◽  
Gas Phase Ion ◽  
Hydride Ion Transfer

Gas phase ion/molecule reactions in a Fourier transform ion cyclotron resonance mass spectrometer have been carried out for reductions of isotopically labelled citraconic (methylmaleic), phenylmaleic, and ethoxymaleic anhydrides by BH4−. In citraconic anhydride the carbonyl group neighbouring the methyl substituent is reduced preferentially in agreement with the ab initio calculations, which show the higher LUMO coefficients at this site. Hydride ion transfer to the olefinic double bond occurs as well; however, in that case no preference for either of the carbon atoms is observed. In phenylmaleic anhydride strong indications are found for a theoretically unexpected hydride ion transfer to the phenyl ring. For ethoxymaleic anhydride experimental evidence is presented showing hydride ion transfer to the carbon atom carrying the ethoxy group, which is in agreement with the "best overlap" consideration predicting that this carbon atom bears the highest LUMO coefficient.Most of the hydride transfers from BH4− to the molecules studied seem, therefore, to take place under orbital control rather than under control of long-range ion-induced dipole interactions between reactants.

Determination of the compound class and functional groups in protonated analytes via diagnostic gas‐phase ion‐molecule reactions

2021 ◽  
Author(s):  
Judy Kuan‐Yu Liu ◽  
Edouard Niyonsaba ◽  
Kawthar Z. Alzarieni ◽  
Victoria M. Boulos ◽  
Ravikiran Yerabolu ◽  
...  
Keyword(s):  
Gas Phase ◽  
Functional Groups ◽  
Ion Molecule Reactions ◽  
Gas Phase Ion

Gas-Phase Ion-Molecule Reactions: A Model for the Determination of Biologically Reactive Electrophilic Contaminants in the Environment

1994 ◽  
Vol 66 (11) ◽  
pp. 1902-1910 ◽  
Author(s):  
Jody A. Freeman ◽  
Jodie V. Johnson ◽  
Richard A. Yost ◽  
Douglas W. Kuehl
Keyword(s):  
Gas Phase ◽  
Ion Molecule Reactions ◽  
Gas Phase Ion

Bimolecular production of gas phase ionic hydrates by ion cyclotron resonance spectroscopy

1980 ◽  
Vol 58 (8) ◽  
pp. 863-865 ◽  
Author(s):  
R. L. Clair ◽  
T. B. McMahon
Keyword(s):  
Gas Phase ◽  
Cyclotron Resonance ◽  
Resonance Spectroscopy ◽  
Ion Cyclotron Resonance ◽  
Ion Chemistry ◽  
Ion Molecule Reactions ◽  
Hydronium Ion ◽  
Dominant Feature ◽  
Ion Cyclotron ◽  
Gas Phase Ion

The gas phase ion–molecule reactions of α,α,α′,α′ tetrafluorodimethyl ether both alone and in mixtures with water have been examined. The dominant feature of the ion chemistry of these mixtures is the sequential bimolecular production of the hydrated hydronium ion, H5O2+. Two independent mechanistic pathways for production of H5O2+ are outlined arising from reaction of H3O+ with (CF2H)2O and from CF2H—O=CHF+ with H2O. Implications for examination of solvent switching equilibria are discussed.

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