scholarly journals Determination of the gas-phase acidities of cysteine-polyalanine peptides using the extended kinetic method

2007 ◽  
Vol 18 (2) ◽  
pp. 188-194 ◽  
Author(s):  
John P. Tan ◽  
Jianhua Ren
Keyword(s):  
Gas Phase ◽  
Kinetic Method

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.

Automatic kinetic method for the determination of reduced glutathione in blood

1992 ◽  
Vol 269 (2) ◽  
pp. 273-279 ◽  
Author(s):  
Rafael Jiménez-Prieto ◽  
Antonio Velasco ◽  
Manuel Silva ◽  
Dolores Pérez-Bendito
Keyword(s):  
Reduced Glutathione ◽  
Kinetic Method

New method for determination of heats of thermal gas-phase reactions yielding intermediates

1996 ◽  
Vol 45 (1) ◽  
pp. 56-59
Author(s):  
N. N. Buravtsev ◽  
Yu. A. Kolbanovskii ◽  
A. A. Ovsyannikov
Keyword(s):  
Gas Phase ◽  
New Method ◽  
Gas Phase Reactions
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