Concepts of sterically hindered resonance and buttressing effect: gas-phase acidities of methyl-substituted benzoic acids and basicities of their methyl esters

1993 ◽  
Vol 115 (25) ◽  
pp. 12071-12078 ◽  
Author(s):  
Michele Decouzon ◽  
Peter Ertl ◽  
Otto Exner ◽  
Jean Francois Gal ◽  
Pierre Charles Maria
Keyword(s):  
Gas Phase ◽  
Methyl Esters ◽  
Benzoic Acids ◽  
Sterically Hindered ◽  
Substituted Benzoic Acids

scholarly journals Analysis of the Gas Phase Acidity of Substituted Benzoic Acids Using Density Functional Concepts

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1631
Author(s):  
Jorge A. Amador-Balderas ◽  
Michael-Adán Martínez-Sánchez ◽  
Ramsés E. Ramírez ◽  
Francisco Méndez ◽  
Francisco J. Meléndez
Keyword(s):  
Gas Phase ◽  
Density Functional ◽  
Chemical Potential ◽  
Fukui Function ◽  
Ortho Position ◽  
Benzoic Acids ◽  
Functional Theory ◽  
Resonance Effects ◽  
Gas Phase Acidity ◽  
Substituted Benzoic Acids

A theoretical study of the effect of the substituent Z on the gas phase acidity of substituted benzoic acids ZC6H4COOH in terms of density functional theory descriptors (chemical potential, softness and Fukui function) is presented. The calculated gas phase ΔacidG° values obtained were close to the experimental ones reported in the literature. The good relationship between the ΔacidG° values and the electronegativity of ZC6H4COOH and its fragments, suggested a better importance of the inductive than polarizability contributions. The balance of inductive and resonance contributions of the substituent in the acidity of substituted benzoic acids showed that the highest inductive and resonance effects were for the -SO2CF3 and -NH2 substituents in the para- and ortho-position, respectively. The Fukui function confirmed that the electron-releasing substituent attached to the phenyl ring of benzoic acid decreased the acidity in the trend ortho > meta > para, and the electron-withdrawing substituent increased the acidity in the trend ortho < meta < para.

Correction. Methyl Esters of Substituted Benzoic Acids

1952 ◽  
Vol 74 (24) ◽  
pp. 6319-6319
Author(s):  
Robert West ◽  
Severo Ornstein ◽  
Donald McKee ◽  
Robert Layzer
Keyword(s):  
Methyl Esters ◽  
Benzoic Acids ◽  
Substituted Benzoic Acids

ChemInform Abstract: Non-Classical Buttressing Effect: Gas-Phase Ionization of Some Methyl- Substituted Benzoic Acids.

ChemInform ◽  
2010 ◽  
Vol 27 (28) ◽  
pp. no-no
Author(s):  
M. DECOUZON ◽  
O. EXNER ◽  
J.-F. GAL ◽  
P.-C. MARIA
Keyword(s):  
Gas Phase ◽  
Benzoic Acids ◽  
Substituted Benzoic Acids

Application of the Hammett equation in the esterification of substituted benzoic acids, catalyzed by AlPO4 in the gas phase

1983 ◽  
Vol 61 (2) ◽  
pp. 230-234 ◽  
Author(s):  
J. V. Sinisterra ◽  
J. M. Marinas ◽  
A. Llobera
Keyword(s):  
Benzoic Acid ◽  
Gas Phase ◽  
Surface Reaction ◽  
Adsorption Process ◽  
Positive Charge ◽  
Kinetic Constant ◽  
Benzoic Acids ◽  
Hammett Equation ◽  
Substituted Benzoic Acids ◽  
First Time

The Hammett equation has for the first time been applied to the esterification in the gas phase of m-MeO, p-MeO, m-Me, p-Me, H, m-NO2, m-Cl, and m-Br benzoic acids, catalyzed by AlPO4 of the F type. It is shown that the Hammett equation could be applied to the adsorption equilibrium constant, KA, and to the apparent kinetic constant, [Formula: see text] The KA and [Formula: see text] values used in this paper have been taken from a study by the same authors. The m-NO2 benzoic acid is in disagreement with the general behavior of the other acids in the application of the Hammett equation to the adsorption process. The p-MeO benzoic acid is in disagreement with the behavior of the acids in the application of the equation to the surface reaction. In these cases, the ρ values were negative. It can be deduced that a positive charge is generated in the adsorption process and in the surface reaction. The AAc2 mechanism is discussed according to the values of ρ, and a more detailed mechanism is proposed. The separation of the enthalpic and entropic contributions to the substituent effect is carried out. [Formula: see text] and[Formula: see text] are nearly 50% in the adsorption process. In the surface reaction, the entropie contribution is greater (72.5%) than the enthalpic (27.5%).

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