ChemInform Abstract: FLASH-PHOTOLYTIC GENERATION OF ACETOPHENONE ENOL. THE KETO-ENOL EQUILIBRIUM CONSTANT AND PKA OF ACETOPHENONE IN AQUEOUS SOLUTION

1985 ◽  
Vol 16 (6) ◽  
Author(s):  
Y. CHIANG ◽  
A. J. KRESGE ◽  
J. WIRZ
Keyword(s):  
Aqueous Solution ◽  
Equilibrium Constant

Schiff base equilibria. I. Formation and distribution of N-n-butylsalicylideneimine

1965 ◽  
Vol 18 (3) ◽  
pp. 329 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Distribution Coefficient ◽  
Equilibrium Constant ◽  
Neutral Form ◽  
Phenolic Group

The equilibrium constant governing the formation of a Schiff base from salicylaldehyde and n-butylamine in aqueous solution has been evaluated by spectrophotometry as 5.62 x 104. The pK of the phenolic group of the Schiff base is 12.0. These constants have been used to account for the distribution of salicylaldehyde between water and toluene in the presence of butylamine. The neutral form of the Schiff base has a distribution coefficient of 1.9 x 103.

Absorption of NO in Aqueous Solution of Co(II)-en:  Determination of the Equilibrium Constant

2007 ◽  
Vol 52 (3) ◽  
pp. 762-765 ◽  
Author(s):  
Bintao Liu ◽  
Hua Chen ◽  
Yanpeng Mao ◽  
Wende Xiao
Keyword(s):  
Aqueous Solution ◽  
Equilibrium Constant

scholarly journals Thermodynamics of ester and orthoester formation from trifluoroacetic acid

1976 ◽  
Vol 54 (2) ◽  
pp. 202-209 ◽  
Author(s):  
J. Peter Guthrie
Keyword(s):  
Aqueous Solution ◽  
Free Energy ◽  
Equilibrium Constant ◽  
Trifluoroacetic Acid ◽  
Sodium Methoxide ◽  
Standard Free Energy ◽  
Steric Effects ◽  
Addition Reactions ◽  
Free Energies ◽  
Acetic Acids

The equilibrium constant for the addition of sodium methoxide to methyl trifluoroacetate, in methanol as solvent, has been measured by 19F nmr, and is 7 M−1. From this was calculated an equilibrium constant, 2 × 10−4 M−1, for addition of methanol to the ester. The equilibrium constant for formation of methyl trifluoroacetate in aqueous solutions is 0.06 M−1. These results, with literature data, permit calculation of the free energies of formation in aqueous solution of orthotrifluoroacetic acid and its mono-, di-, and trimethyl esters. These in turn permit calculation of the standard free energy changes for addition of water and methanol to trifluoroacetic acid and its methyl ester. These combined with the analogous values for formic and acetic acids permit evaluation of ρ* values for these addition reactions. Linear plots are obtained if correction is made for steric effects, and the ρ* values are somewhat larger, 2.1–2.9, than was observed for the analogous carbonyl addition reactions.

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