General acid catalysis in benzoic acid–Crystal Violet carbinol base reactions in toluene

Gupta, Susanta K. Sen; Mishra, Shuddhodan P.; Rani, Varsha; Arvind, Udai

doi:10.1002/kin.20628

Cited by 3 publications

(5 citation statements)

References 37 publications

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“…Further, log k α as well as log k cat versus log K for all these benzoic acids follows significantly the Brønsted relationship. The degree of proton transfer in the transition state thus found is 50–60% when the acid acts as a monomer but may rise to 80–90% when it acts as some hyperacidic homoconjugated acid complex . The result is in agreement with the observed increase in log k α with solvent dielectric constant.…”

Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Asupporting

confidence: 85%

“…The following statistically well‐significant correlations exemplify the superiority of log k +1 (for mono‐substituted benzoic acids)/log K (for di‐substituted benzoic acids) over the other parameters: Ortho ‐substituted benzoic acids:

normallog k_{+ 1} ((), toluene) = 1.50 normallog K ((), toluene) - 0.73

normallog k_{+ 1} ((), toluene) = 1.47 normallog K_{normalB normalH normalA} ((), benzene) - 4.51

normallog k_{+ 1} ((), toluene) = 1.14 normallog K ((), chlorobenzene) + 2.68

normallog k_{α} ((), toluene) = 0.53 normallog K ((), toluene) + 0.33

normallog k_{cat} ((), toluene) = 0.96 normallog K ((), toluene)

normallog k_{+ 1} ((), toluene) = - 2.46 p K_{a} ((), H_{2} normalO) + 12.18

Meta ‐substituted benzoic acids:

normallog k_{+ 1} ((), toluene) = 1.27 normallog K ((), toluene) - 0.43

…”

Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Amentioning

confidence: 86%

“…In Eqn , k α is the catalytic constant for the monomer acid, and k β and k γ are the constants for net catalytic action by the dimeric and trimeric acid species, respectively, which may be positive or negative, with the contribution of the successive terms decreasing rapidly. The catalytic behavior is alternatively expressible as Eqn , where k cat is the composite catalytic constant and p is an acid exponent (generally p ≈ 1 except for strong enough acids for which p > 1) …”

Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Amentioning

confidence: 99%

“…The correlation of log k α for ortho ‐substituted benzoic acids,

normallog k_{α} ((), toluene) = 2.24 σ_{I} + 1.17 σ_{R} + 1.36

may be compared with that for meta ‐substituted benzoic acids,

normallog k_{α} ((), toluene) = 3.02 σ_{I} + 1.29 σ_{R} + 1.36

…”

Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Amentioning

confidence: 99%

“…A critical analysis of the findings on the effects of reactant concentrations, temperature, acid structure, and properties of apolar aprotic solvents on acid (HA)–dye carbinol base (D) rate equilibria led to the elucidation of a mechanism for abnormally “slow” proton transfer between HA and D in such solvents. The mechanism consists of a fast equilibrium between the reactant components and an intermediate 1:1 hydrogen‐bonded complex D•••HA formed by the fast diffusional approach of D and HA followed by the rate‐limiting proton transfer along the hydrogen bond to form the ion‐pair product, DH + A – , under the combined influence of monomer HA catalyst, non‐reactive cyclic dimer (HA) 2 inhibitor, and hyperacidic open‐chain dimer H(HA 2 ) catalyst (the contribution of each species depending on the magnitude of initial concentration of HA) through a dipolar transition state with ~60% charge separation accompanied by the release of enough energy due to delocalization of charge in the incipient dye carbocation and sufficiently large negative entropy of activation

normalD + normalH normalA ⇌ normalD \cdot \cdot \cdot normalH normalA ((), fast)

normalD \cdot \cdot \cdot normalH normalA + normalH normalA \to {normalD normalH}^{+} A^{-} + normalH normalA ((), slow)

normalD \cdot \cdot \cdot normalH normalA + {(H A)}_{2} \to {normalD normalH}^{+} A^{-} + 2 normalH normalA ((), slow)

…”

Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Amentioning

confidence: 99%

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Proton transfer reactions in apolar aprotic solvents

Gupta

2015

J of Physical Organic Chem

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Proton transfer reactions are advantageously investigated in low‐dielectric‐constant apolar aprotic solvents where specific solute–solvent interactions are greatly minimized, if not eliminated, and proton transfer occurs directly. An intriguing feature of these reactions is their general acid/base‐catalyzed kinetics with a timescale over microseconds to minutes. Proton‐coupled electron transfer (PCET), a great promise in the development of renewable energy sources, is an emerging application of the reactions. This article is an updated review of the post‐1980 developments in understanding the mechanism of proton transfer reactions, quantitative structure–reactivity relationships, acid/base‐catalyzed molecular rearrangements, reverse trends between acidity parameters and 13C δco (a measure of electron population at the carboxyl carbon) in aromatic carboxylic acids, coupling of proton transfer with electron transfer, and PCET reactions in suitably designed model systems in apolar aprotic solvents for renewable energy devices. Copyright © 2015 John Wiley & Sons, Ltd.

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Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Asupporting

confidence: 85%

normallog k_{+ 1} ((), toluene) = 1.50 normallog K ((), toluene) - 0.73

normallog k_{+ 1} ((), toluene) = 1.47 normallog K_{normalB normalH normalA} ((), benzene) - 4.51

normallog k_{+ 1} ((), toluene) = 1.14 normallog K ((), chlorobenzene) + 2.68

normallog k_{α} ((), toluene) = 0.53 normallog K ((), toluene) + 0.33

normallog k_{cat} ((), toluene) = 0.96 normallog K ((), toluene)

normallog k_{+ 1} ((), toluene) = - 2.46 p K_{a} ((), H_{2} normalO) + 12.18

Meta ‐substituted benzoic acids:

normallog k_{+ 1} ((), toluene) = 1.27 normallog K ((), toluene) - 0.43

…”

Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Amentioning

confidence: 86%

Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Amentioning

confidence: 99%

“…The correlation of log k α for ortho ‐substituted benzoic acids,

normallog k_{α} ((), toluene) = 2.24 σ_{I} + 1.17 σ_{R} + 1.36

may be compared with that for meta ‐substituted benzoic acids,

normallog k_{α} ((), toluene) = 3.02 σ_{I} + 1.29 σ_{R} + 1.36

…”

Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Amentioning

confidence: 99%

normalD + normalH normalA ⇌ normalD \cdot \cdot \cdot normalH normalA ((), fast)

normalD \cdot \cdot \cdot normalH normalA + normalH normalA \to {normalD normalH}^{+} A^{-} + normalH normalA ((), slow)

normalD \cdot \cdot \cdot normalH normalA + {(H A)}_{2} \to {normalD normalH}^{+} A^{-} + 2 normalH normalA ((), slow)

…”

Section: Proton Transfer Rate Equilibria In Apolar Aprotic Solvents Amentioning

confidence: 99%

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Proton transfer reactions in apolar aprotic solvents

Gupta

2015

J of Physical Organic Chem

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Removal of Remazol Brilliant Blue R from Aqueous Solution by Adsorption Using Pineapple Leaf Powder and Lime Peel Powder

Rahmat

Ali

Salmiati

et al. 2016

Water Air Soil Pollut

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Influence of Substitutes on the Rate of the Reaction of Orthosubstituted Benzoic Acids WTH Aniline, Catalyzed by Polybutoxytitanates

Shteinberg¹

2021

Ukr. Chem. Journ.

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The polybutoxytitanates catalysis of aniline acylation by orthosubstituted benzoic acids leads to the production of substituted benzanilides. Catalytic rate constants of the second order reaction (the first with respect to aniline and ortho-substituted benzoic acid; boiling ortho=xylene, 145°C) correlate well according to the Hammett and Bronsted equations with straight line segments with ρ=1.93 and α=0.66, in contrast to the reaction of aniline with meta- and parasubstituted benzoic acids and substituted anilines with benzoic acid. This dependence drops out 2=nitrobenzoic and 1=naphthoic acids, which have relatively low reactivity and the greatest steric hindrances both for nucleophilic attack by aniline and for possible coordination with catalytically active centers of the corresponding ortho-substituted titanium polybutoxybenzoates formed in situ. Based on these data, the previously proposed mechanism of bifunctional catalysis due to titanium polybutoxybenzoates and their complexes with meta- and parasubstitutedbenzanilides was supplemented by the possibility of the steric inhibition of reaction by the most bulky substituents and chelate structures formation of orthosubstituted benzoic acids and their anilides with individual titanium atoms of the catalyst, as well as the simultaneous H-bonding of the amino group hydrogen atoms of aniline, which leads to its activation to a nucleophilic attack, with a carbonyl group and an orthopositioned substituent of the orthobenzoate ligand in the coordination sphere of titanium. Taking into account such chelation and steric barriers, as well as inhibition of acid catalysis due to the formation of the imide form of anilides, containing electron-withdrawing substituents, the equations for the rate constants of the catalytic reaction of ortho-substituted benzoic acids with aniline are derived, corresponding to the experimentally obtained Hammett dependence.

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General acid catalysis in benzoic acid–Crystal Violet carbinol base reactions in toluene

Cited by 3 publications

References 37 publications

Proton transfer reactions in apolar aprotic solvents

Proton transfer reactions in apolar aprotic solvents

Removal of Remazol Brilliant Blue R from Aqueous Solution by Adsorption Using Pineapple Leaf Powder and Lime Peel Powder

Influence of Substitutes on the Rate of the Reaction of Orthosubstituted Benzoic Acids WTH Aniline, Catalyzed by Polybutoxytitanates

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