A Kinetic Study on Nucleophilic Displacement Reactions of Aryl Benzenesulfonates with Potassium Ethoxide: Role of K+Ion and Reaction Mechanism Deduced from Analyses of LFERs and Activation Parameters

2012 ◽  
Vol 78 (2) ◽  
pp. 490-497 ◽  
Author(s):  
Ik-Hwan Um ◽  
Ji-Sun Kang ◽  
Young-Hee Shin ◽  
Erwin Buncel
Keyword(s):  
Reaction Mechanism ◽  
Kinetic Study ◽  
Activation Parameters ◽  
Nucleophilic Displacement ◽  
Displacement Reactions

Effect of electron correlation on SN2 activation barriers. Fourth-order MBPT calculations

1988 ◽  
Vol 53 (10) ◽  
pp. 2239-2249 ◽  
Author(s):  
Ivan Černušák ◽  
Miroslav Urban
Keyword(s):  
Gas Phase ◽  
Barrier Height ◽  
Fourth Order ◽  
Electron Correlation ◽  
Activation Barriers ◽  
Vital Importance ◽  
Nucleophilic Displacement ◽  
Displacement Reactions ◽  
Individual Contributions

The activation barriers for a series of model gas-phase nucleophilic displacement reactions have been calculated at the MBPT(4)/DZ + P + D level. Electron correlation significantly reduces the barrier height, in most cases by about 50%. The role of individual contributions up to the fourth order MBPT is analyzed in detail showing the vital importance of single and triple excitations.

Kinetics and Mechanism of the Oxidation of Benzyl Alcohol and Benzaldehyde by Aqueous Sodium Dichromate

1975 ◽  
Vol 53 (24) ◽  
pp. 3709-3713 ◽  
Author(s):  
Donald G. Lee ◽  
Udo A. Spitzer
Keyword(s):  
Reaction Mechanism ◽  
Kinetic Study ◽  
Benzyl Alcohol ◽  
Oxidation Rate ◽  
Activation Parameters ◽  
Sodium Dichromate ◽  
Benzyl Alcohols ◽  
Aqueous Sodium ◽  
Entropy Of Activation ◽  
The Difference

A kinetic study of the oxidation of a series of substituted benzyl alcohols and benzaldehydes by neutral aqueous sodium dichromate has been completed. The aldehydes are more resistant to oxidation because the reaction mechanism presumably involves hydration prior to oxidation, and under the conditions employed the extent of this hydration is suppressed. These conclusions are consistent with the activation parameters which indicate that the difference in oxidation rate is due to a more negative entropy of activation for the aldehydes.

scholarly journals The Effect of the ortho Nitro Group in the Solvolysis of Benzyl and Benzoyl Halides

2019 ◽  
Vol 20 (16) ◽  
pp. 4026
Author(s):  
Kyoung-Ho Park ◽  
Chan Joo Rhu ◽  
Jin Burm Kyong ◽  
Dennis N. Kevill
Keyword(s):  
Kinetic Study ◽  
Nitro Group ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Similar Rate ◽  
Wide Range

A kinetic study was carried out on the solvolysis of o-nitrobenzyl bromide (o-isomer, 1) and p-nitrobenzyl bromide (p-isomer, 3), and o-nitrobenzoyl chloride (o-isomer, 2) in a wide range of solvents under various temperatures. In all of the solvents without aqueous fluoroalcohol, the reactions of 1 were solvolyzed at a similar rate to those observed for 3, and the reaction rates of 2 were about ten times slower than those of the previously studied p-nitrobenzoyl chloride (p-isomer, 4). For solvolysis in aqueous fluoroalcohol, the reactivity of 2 was kinetically more reactive than 4. The l/m values of the extended Grunwald–Winstein (G–W) equation for solvolysis of 1 and 2 in solvents without fluoroalcohol content are all significantly larger than unity while those in all the fluoroalcohol solvents are less than unity. The role of the ortho-nitro group as an intramolecular nucleophilic assistant (internal nucleophile) in the solvolytic reaction of 1 and 2 was discussed. The results are also compared with those reported earlier for o-carbomethoxybenzyl bromide (5) and o-nitrobenzyl p-toluenesulfonate (7). From the product studies and the activation parameters for solvolyses of 1 and 2 in several organic hydroxylic solvents, mechanistic conclusions are drawn.

scholarly journals A kinetic and mechanistic study of the osmium(VIII)-catalysed oxidation of crotyl alcohol by hexacyanoferrate(III) in aqueous Alkaline medium

2020 ◽  
Vol 44 (5-6) ◽  
pp. 295-300
Author(s):  
Priyamvada Sharma ◽  
Riya Sailani ◽  
Anita Meena ◽  
Chandra Lata Khandelwal
Keyword(s):  
Reaction Mechanism ◽  
Alkaline Medium ◽  
Activation Parameters ◽  
Mechanistic Study ◽  
Aqueous Alkaline Medium ◽  
Crotyl Alcohol ◽  
Catalysed Oxidation ◽  
Entropy Of Activation ◽  
Eyring Equation

The kinetics and mechanism of the osmium(VIII)-catalysed oxidation of crotyl alcohol by hexacyanoferrate(III) in aqueous alkaline medium is studied. The role of the osmium(VIII) catalyst is delineated to account for the experimental observations. A plausible reaction mechanism is suggested. Activation parameters such as the energy and entropy of activation are evaluated by employing the Eyring equation and are found to be 36.833 kJ mol−1 and −141.518 J K−1 mol−1, respectively.

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