Contribution to the study of the esterification mechanism in the gas phase of substituted benzoic acids on AlPO4

1984 ◽  
Vol 25 (3-4) ◽  
pp. 181-186
Author(s):  
A. Llobera ◽  
J. V. Sinisterra
Keyword(s):  
Gas Phase ◽  
Benzoic Acids ◽  
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.

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%).

Electrostatic effects on ionization equilibria: Solvent dependence

1984 ◽  
Vol 49 (1) ◽  
pp. 179-189 ◽  
Author(s):  
Karel Kalfus ◽  
Zdeněk Friedl ◽  
Otto Exner
Keyword(s):  
Gas Phase ◽  
Carboxylic Acids ◽  
Dissociation Constants ◽  
Aprotic Solvents ◽  
Benzoic Acids ◽  
Cavity Model ◽  
Electrostatic Effects ◽  
Solvent Dependence ◽  
Ionization Equilibria ◽  
Substituted Benzoic Acids

Apparent dissociation constants of 3-substituted bicyclo[2,2,2]-octane-1-carboxylic acids I-III and of several substituted benzoic acids were measured in four pure solvents. The results - together with numerous literature data concerning dissociation in other solvents and in the gas phase - were compared with the prediction of the electrostatic theory. The theory fails to reproduce the essential features of the solvent dependence as it predicts generally too small effects and does not differentiate between protic and aprotic solvents. The mentioned goal cannot be achieved by any more sophisticated cavity model or by any other theory as far as it characterizes the solvent only through its bulk permittivity.

scholarly journals Theoretical study of the energetics of carboxylic O–H bond cleavage in the para- and meta-substituted benzoic acid derivatives

2015 ◽  
Vol 8 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Peter Škorňa ◽  
Adam Vagánek ◽  
Peter Poliak ◽  
Erik Klein
Keyword(s):  
Gas Phase ◽  
Theoretical Study ◽  
Bond Cleavage ◽  
Computational Method ◽  
Benzoic Acids ◽  
Proton Affinities ◽  
Benzoic Acid Derivatives ◽  
Hammett Constants ◽  
Carboxylate Anions ◽  
Substituted Benzoic Acids

Abstract Gas phase bond dissociation enthalpies (BDE) of para- and meta-substituted benzoic acids and proton affinities (PA) of their carboxylate anions were investigated using the B3LYP/6-311++G** method for 15 substituents with various electron-donating and electron-withdrawing effects. The employed computational method provided BDE and PA values in fair agreement with experimental data. The substituent effect on BDEs and PAs was analyzed in terms of Hammett constants. Found dependences exhibit satisfactory linearity and enable quick estimation of BDEs and PAs from the Hammett constants.

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