Kinetics and Mechanism of the Oxidation of Oxyacids of Phosphorus by Benzimidazolium Dichromate

Kumar, Rakesh; Panday, Dinesh; Kothari, Seema

doi:10.3184/146867811x13103063934104

Cited by 3 publications

(2 citation statements)

References 14 publications

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“…The reaction rate increased directly with the increasing concentration of the alcohols 22 (Table 1). The plot of 1/k obs versus 1/[alcohol] plot was linear with the slop on the rate ordinate 23 suggesting the Michaelis-Menten type of kinetics with respect to the alcohols (Fig. 3).…”

Section: Structure Of Benzimidazolium Fluorochromatementioning

confidence: 86%

Kinetics and Mechanism of Oxidation of Aliphatic Secondary Alcohols by Benzimidazolium Fluorochromate in Dimethyl Sulphoxide Solvent

2021

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Oxidation of secondary alcohols is an important part of synthetic organic chemistry. Various studies are carried out at different reaction conditions to determine the best mechanistic pathways. In our study, oxidation of different secondary alcohols was done by using Benzimidazolium Fluorochromate in Dimethyl Sulphoxide, which is a non-aqueous solvent. Oxidation resulted in the formation of ketonic compounds. The reaction showed first order kinetics both in BIFC and in the alcohols. Hydrogen ions were used to catalyze the reaction. We selected four different temperatures to carry out our study. The correlation within the activation parameters like enthalpies and entropies was in accordance with the Exnerʼs criterion. The deuterated benzhydrol (PhCDOHPh) oxidation exhibited an important primary kinetic isotopic effect (kH / kD = 5.76) at 298 K. The solvent effect was studied using the multiparametric equations of Taft and Swain. There was no effect of addition of acrylonitrile on the oxidation rate. The mechanism involved sigmatropic rearrangement with the transfer of hydrogen ion taking place from alcohol to the oxidant via a cyclic chromate ester formation.

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Section: Structure Of Benzimidazolium Fluorochromatementioning

confidence: 86%

Kinetics and Mechanism of Oxidation of Aliphatic Secondary Alcohols by Benzimidazolium Fluorochromate in Dimethyl Sulphoxide Solvent

2021

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“…We have been interested in the kinetics and mechanism of the oxidation by newer complexes of Cr(VI). We have published a few reports on the kinetic www.prkm.co.uk and mechanistic aspects of the oxidation by BIDC [3][4][5][6][7][8][9][10]. In continuation of our earlier studies, we report here the kinetics and mechanism of the oxidation of mandelic acid (MA) and nine monosubstituted MAs by BIDC in dimethyl sulfoxide (DMSO), a non-aqueous solvent.…”

Section: Introductionmentioning

confidence: 99%

Kinetics and Correlation Analysis of Reactivity in the Oxidation of Some α-Hydroxy Acids by Benzimidazolium Dichromate

Panday¹,

Kachawa²,

Kothari

2018

Progress in Reaction Kinetics and Mechanism

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Kinetic and mechanistic studies of the oxidation of mandelic acid and nine monosubstituted mandelic acids by benzimidazolium dichromate (BIDC) in dimethyl sulfoxide are discussed with an emphasis on correlation of structure and reactivity. The reactions were of first order with respect to BIDC. However, Michaelis-Menten type kinetics were observed with respect to hydroxy acids. The reactions are catalysed by protons. The deuterium isotope effect for the oxidation of mandelic acid ( kH/ kD = 5.91 at 298 K) indicated an α-C-H bond cleavage in the rate-determining step. An analysis of the solvent effect showed that the role of cationsolvation is major. The reaction showed an excellent correlation with the Hammett σ values, the reaction constant being negative. Based on the kinetic data, analysis of the solvent effect and results of structure-reactivity correlation along with some non-kinetic parameters, a mechanism involving rate-determining oxidative decomposition of the complex through hydride-ion transfer via a cyclic transition state to give the corresponding oxoacid is suggested.

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Kinetics and Correlation Analysis of Reactivity in the Oxidation of Some Alkyl Phenyl Sulfides by Benzimidazolium Dichromate

Pandey

Kothari

2014

Bulletin of the Chemical Society of Japan

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The oxidation of some alkyl phenyl sulfides by benzimidazolium dichromate (BIDC) in dimethyl sulfoxide, to the corresponding sulfoxides, is first order with respect to BIDC. Michaelis–Menten type kinetics was observed with respect to sulfide. Thermodynamic parameters for the complex formation and activation parameters for the decomposition of the complex were calculated. The reaction is proton-catalyzed and the order is less than one. It appears that the BIDCH+ is the active electrophile. An intermediate of composition sulfide–BIDC–H+ has been envisaged. The high value of negative entropy of activation suggests a cyclic transition state in the rate-determining step. The reaction exhibited negative polar reaction constants and a small degree of steric hindrance. The rate of oxidation of sulfide was determined in 19 organic solvents. An analysis of the solvent effect by Swain’s equation indicated that though both the anion and cation solvating powers of the solvent contribute to the observed solvent effect, the role of cation solvation is major. A mechanism involving the rate-determining oxygen atom transfer in complex, formed by a nucleophilic attack of sulfide-sulfur on BIDCH+ in a rapid pre-equilibrium, is suggested to give corresponding sulfoxide via. a cyclic transition state.

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Kinetics and Mechanism of the Oxidation of Oxyacids of Phosphorus by Benzimidazolium Dichromate

Abstract: Oxidation of some lower oxyacids of phosphorus by benzimidazolium dichromate results in the formation of the corresponding oxyacids containing phosphorus in a higher oxidation state, via an intermediate complex formation.

Cited by 3 publications

References 14 publications

Kinetics and Mechanism of Oxidation of Aliphatic Secondary Alcohols by Benzimidazolium Fluorochromate in Dimethyl Sulphoxide Solvent

Kinetics and Mechanism of Oxidation of Aliphatic Secondary Alcohols by Benzimidazolium Fluorochromate in Dimethyl Sulphoxide Solvent

Kinetics and Correlation Analysis of Reactivity in the Oxidation of Some α-Hydroxy Acids by Benzimidazolium Dichromate

Kinetics and Correlation Analysis of Reactivity in the Oxidation of Some Alkyl Phenyl Sulfides by Benzimidazolium Dichromate

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