scholarly journals Determination of the gas-phase acidity of methylthioacetic acid using the Cooks’ kinetic method

2005 ◽  
Vol 16 (4) ◽  
pp. 535-541 ◽  
Author(s):  
Jianhua Ren ◽  
Chirag G. Patel
Keyword(s):  
Gas Phase ◽  
Kinetic Method ◽  
Gas Phase Acidity

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.

Determination of the Gas-Phase Basicity of Betaine and Related Compounds Using the Kinetic Method

1996 ◽  
Vol 118 (1) ◽  
pp. 231-232 ◽  
Author(s):  
Jeffrey S. Patrick ◽  
Sheng S. Yang ◽  
R. Graham Cooks
Keyword(s):  
Gas Phase ◽  
Kinetic Method ◽  
Related Compounds

Structure, Thermochemistry and Reactivity of Protonated Glycolaldehyde

2001 ◽  
Vol 7 (4-5) ◽  
pp. 351-357 ◽  
Author(s):  
Guy Bouchoux ◽  
Florence Penaud-Berruyer ◽  
William Bertrand
Keyword(s):  
Gas Phase ◽  
Kinetic Method ◽  
Critical Energy ◽  
Protonated Form ◽  
Heats Of Formation ◽  
Molecular Orbital Calculations ◽  
Perfect Agreement ◽  
Stable Conformation ◽  
Water Complex

Structures and relative energies of various conformers of the simplest sugar, glycolaldehyde, 1, and its protonated form, [1H]+, were investigated by ab initio molecular orbital calculations. The 298 K heats of formation of the most stable conformers, deduced from the atomization energies at the G2 level, are equal to Δ fH°(1) = −324.8 kJ mol−1 and Δ fH°[1H]+ = 426.0 kJ mol−1. The corresponding proton affinity value is PA(1) = 779.8 kJ mol−1, in perfect agreement with the experimental determination of 783.3 ± 3.8 kJ mol−1 obtained by the kinetic method. A gas-phase basicity value, GB(1), of 745–748 kJ mol−1 is also deduced from theory and experiment. The exclusive dissociation channel of protonated glycolaldehyde, [1H]+, is water loss which leads essentially to the acylium ion [CH3CO]+. The corresponding potential energy profile, investigated at the MP2/6–31G* level, reveals a route via a [CH3CO]+ / water complex after an energy determining step involving a simultaneous 1,2-hydrogen migration and C–O bond elongation. The critical energy of the reaction, evaluated at the G2(MP2,SVP)level, is 170 kJ mol −1 above the most stable conformation of the [1H]+ ion. The 298 K heats of formation of the three most stable [C2H3O]+ ions have been calculated at the G2 level: Δ fH°[CH3CO]+ = 655.0 kJ mol−1, Δ fH°[CH2COH]+ = 833.0 kJ mol−1, Δ fH°[c-CH2CHO]+ = 886.2 kJ mol−1.

scholarly journals Experimental and Computational Studies on the Gas-Phase Acidity of 5,5-Dialkyl Barbituric Acids

2021 ◽  
Author(s):  
Juan Z. Dávalos-Prado ◽  
Javier González ◽  
Josep M. Oliva-Enrich ◽  
Emma J. Urrunaga ◽  
Alexsandre F. Lago
Keyword(s):  
Gas Phase ◽  
Computational Studies ◽  
Gas Phase Acidity
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