Some observations relating to substituent effects in halogenation. Part VII. The kinetics and reactions of toluene and o- and p-xylene with chlorine acetate in aqueous acetic acid and acetic acid–perchloric acid

1976 ◽  
pp. 357-359 ◽  
Author(s):  
Osman M. H. El Dusouqui ◽  
Abdel Rahman H. El Nadi ◽  
Mustapha Hassan ◽  
Ghariballa Yousif
Keyword(s):  
Acetic Acid ◽  
Perchloric Acid ◽  
Substituent Effects ◽  
Aqueous Acetic Acid

scholarly journals Kinetic Evidence of a Common Mechanism in the Oxidation by Chromium(vi) Complexes: Oxidation of Benzyl Alcohol

2000 ◽  
Vol 2000 (3) ◽  
pp. 114-115 ◽  
Author(s):  
Chockalingam Karunakaran ◽  
Sadasivam Suresh
Keyword(s):  
Acetic Acid ◽  
Benzyl Alcohol ◽  
Perchloric Acid ◽  
Mineral Acid ◽  
Common Mechanism ◽  
Aqueous Acetic Acid ◽  
First Order ◽  
Chromium Vi ◽  
Oxidation Of Benzyl Alcohol

The oxidation of benzyl alcohol by dichromate and seven chromium(VI) complexes in aqueous acetic acid in the presence of perchloric acid is first order each in the oxidants, the alcohol and the mineral acid. The oxidation conforms to the isokinetic and Exner relationships and follows a common mechanism.

The Acidity Function of Perchloric Acid in Aqueous Acetic Acid

1954 ◽  
Vol 76 (14) ◽  
pp. 3853-3854 ◽  
Author(s):  
Frederick J. Ludwig ◽  
Kenneth H. Adams
Keyword(s):  
Acetic Acid ◽  
Perchloric Acid ◽  
Aqueous Acetic Acid ◽  
Acidity Function

Chlorination of 2-Phenoxypropanoic Acid with NCP in Aqueous Acetic Acid:  Using a Novel Ortho−Para Relationship and the Para/Meta Ratio of Substituent Effects for Mechanism Elucidation

2007 ◽  
Vol 72 (14) ◽  
pp. 5327-5336 ◽  
Author(s):  
Manuel A. P. Segurado ◽  
João Carlos R. Reis ◽  
Jaime D. Gomes de Oliveira ◽  
Senthamaraikannan Kabilan ◽  
Manohar Shanthi
Keyword(s):  
Acetic Acid ◽  
Substituent Effects ◽  
Aqueous Acetic Acid

Chlorination of N-Phenylbenzenesulfonamides with NCP in Aqueous Acetic Acid. Using the para/meta Ratio of Substituent Effects for Mechanism Elucidation

2004 ◽  
Vol 69 (12) ◽  
pp. 2253-2275 ◽  
Author(s):  
João Carlos R. Reis ◽  
Manuel A. P. Segurado ◽  
Jaime D. Gomes de Oliveira ◽  
Senthamaraikannan Kabilan ◽  
Krishnasamy Suganya
Keyword(s):  
Acetic Acid ◽  
Nitrogen Atom ◽  
Rate Constants ◽  
Substituent Effects ◽  
Aqueous Acetic Acid ◽  
Isokinetic Temperature ◽  
Isokinetic Relationship ◽  
Rate Determining Step ◽  
Different Temperatures ◽  
Energy Ratios

Rate constants were measured for the oxidative chlorination reaction of N-phenylbenzenesulfonamide 2 and twelve ortho-, nine meta- and twelve para-substituted derivatives in the aniline moiety, using 1-chloro-3-methyl-2,6-diphenylpiperidin-4-one (1) as chlorinating agent. The kinetics was run in 50% (v/v) aqueous acetic acid acidified with perchloric acid under pseudo-first-order conditions with respect to 1 at five different temperatures between 298 and 318 K. The dependence of rate constants on temperature was analysed in terms of the isokinetic relationship (IKR). The resulting isokinetic temperature was estimated to be 513 K. Using the Linert's theory of the IKR, the experimental isokinetic temperature was interpreted as evidence for the preferential involvement of water molecules in the formation of activated complexes. The dependence of the rate constants on the substituents was analysed using the tetralinear extension of the Yukawa-Tsuno equation for the effects of meta and para substituents. A positively charged transition state was suggested by an experimental value r+ = 0.39 for the resonance demand, which was found to be insensitive to temperature variation. The parameter λ for the para/meta ratio of substituent effects was estimated to be 0.952. The electrostatic modelling of λ values was re-examined in the light of the recent calculations of the energies of interaction between charged and/or dipolar groups by Exner and Böhm. Based on energy ratios, the electrostatic method was shown to remain valid for the purpose of modelling λ values. The experimental λ value for the reaction indicates the formation of an activated complex possessing an electric charge in the vicinity of the nitrogen atom of the substrate. The electrophilic attack on the substrate nitrogen atom by the protonated chlorinating reagent has been proposed as the rate-determining step, with the last step being the fast rearrangement of the intermediate N-chloro-N-phenylbenzenesulfonamidium cation into the products.

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