Quinolinium Fluorochromate Research Articles

Chromium, fluorine and nitrogen tri-doped graphene sheets as an active electrode material for symmetric supercapacitors

The tri-doped (chromium, fluorine and nitrogen) graphene sheets (CFNG) have been prepared using quinolinium fluorochromate (QFC) as the single and novel source. Graphene oxide (GO) and CFNG were synthesized by modified Hummers method and simple hydrothermal method, respectively, and their electrochemical properties towards supercapacitor were studied. The HR-TEM images provide the crumpled sheet like morphology of CFNG. XPS reveals the presence of Cr, F and N in CFNG. The electrochemical studies such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge (GCD) were carried out using 1 M H2SO4 to evaluate the capacitive behaviour in three-electrode cells. A better storage capacitive behaviour of about 363 F/g at a current density of 0.5 A/g was achieved by CFNG. The capacitive performance of CFNG was also tested in two electrode cells, in which, a symmetric device was fabricated with CFNG, which exhibited specific capacitance of 160 F/g for 0.5 A/g. The symmetric CFNG supercapacitor device further delivers respective energy density and power density of 14.23 Wh/kg and 300 W/Kg with excellent capacitance retention of 98.8% and coulombic efficiency of 98.3% for over 1000 charge-discharge cycles. The electrochemical results were indicating that CFNG would be a potential candidate as an active electrode material for supercapacitors.

CORRELATION ANALYSIS OF REACTIVITY IN THE OXIDATION OF SUBSTITUTED BENZALDEHYDES BY QUINOLINIUM FLUOROCHROMATE

Oxidation of thirty six monosubstituted benzaldehydes by quinolinium fluorochromate (QFC) in dimethylsulphoxide (DMSO), leads to the formation of corresponding benzoic acids. The reaction is of first order with respect to QFC. A Michaelis-Menten type kinetics was observed with respect to the reactants. The reaction is promoted by hydrogen ions; the hydrogen‑ion dependence has the form k obs =a +b[H + ]. The oxidation of [ 2 H]benzaldehyde (PhCDO) exhibited a substantial primary kinetic isotope effect. The reaction was studied in nineteen different organic solvents and the effect of solvent was analysed using Taft's and Swain's multi-parametric equations. The rates of the oxidation of para‑ and meta‑substituted benzaldehydes showed excellent correlation in terms of Charton’s triparametric LDR equation, whereas the oxidation of ortho-substituted benzaldehydes were correlated well with tetraperametric LDRS equation. The oxidation of para-substituted benzaldehydes is more susceptible to the delocalized effect than is the oxidation of ortho- and meta- substituted compounds, which display a greater dependence on the field effect. The positive value of h suggests the presence of an electron-deficient reaction centre in the rate-determining step. The reaction is subjected to steric acceleration by the ortho-substituents. A suitable mechanism has been proposed.

ChemInform Abstract: Quinolinium Fluorochromate - A New Reagent for the Oxidation of Organic Compounds.

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ChemInform Abstract: Oxidative Transformation of Alcohols and Oximes to Carbonyl Compounds by Quinolinium Fluorochromate (QFC).

ChemInform Abstract: Oxidative Transformation of Alcohols and Oximes to Carbonyl Compounds by Quinolinium Fluorochromate (QFC).

Aquachloroiridium (III)-catalyzed oxidation of some unsaturated acids in acetone by acidic quinolinium fluorochromate

Kinetic investigation in Ir(III)-catalyzed oxidation of fumaric acid (FA) and crotonic acid (CA) in an acidified solution of quinolinium fluorochromate (QFC) has been studied in the temperature range of 30–45°C. First-order kinetics was observed in the case of catalyst Ir(III) as well as oxidant QFC. The order of reaction with respect to substrate (unsaturated acids) was found to be zero. Increase in [Cl−] showed fractional negative order. The influence of [H+] and ionic strength on the rate was found to be insignificant. The main product of oxidation of fumaric acid (FA) and crotonic acid (CA) were identified as pyruvic acid and acetone, respectively. The reaction has been studied in ten different solvents. The first-order rate constant had no effect with decrease in the dielectric constant of the medium. The values of rate constants observed at four different temperatures (30, 35, 40 and 45°C) were utilized to calculate the activation parameters. A suitable mechanism in conformity with the kinetic observations has been proposed and the rate law has been derived on the basis of obtained data. A transient complex formed between IrIII and oxidant in a slow and rate-determining step, further reacts with substrate to give the products in a series of fast steps.

Effect of excess free energy of solvents on the oxidation of methionine by quinolinium fluorochromate: A kinetic study

The oxidation of methionine by quinolinium fluorochromate (QFC) was studied in the presence of chloroacetic acid, in water/organic solvent mixtures of varying excess molar free energy function. The reaction is first order with respect to both QFC and acid. The reaction rates were determined at different temperatures and the activation parameters computed. The rate data was correlated with different solvent parameters using linear multiple regression analysis. From the results, information on the solvent-reactants and the solvent-transition state interactions was obtained. .

BIFC and QFC promoted rapid and cleaner aromatization of 1,4‐dihydropyridines under solvent‐free condition

Abstractmagnified imageThis communication expresses aromatisation of 1,4‐dihydropyridines to pyridine derivatives with the help of alumina supported benzimidazolium fluorochromate (BIFC) and quinolinium fluorochromate (QFC) as oxidants under solvent‐free microwave irradiation. Moderate to excellent yield (80‐98%) of pyridine derivatives were achieved by this methodology.

Quinolinium Fluorochromate: An Efficient and Convenient Reagent for Oxidative Cleavage of Thioacetals to Their Parent Carbonyl Compounds.

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Quinolinium Fluorochromate: An Efficient and Convenient Reagent for Oxidative Cleavage of Thioacetals to Their Parent Carbonyl Compounds

Deprotection of thioacetals to their parent carbonyl compounds in high yields has been carried out using quinolinium fluorochromate under mild conditions.

Quinolinium Fluorochromate: An Efficient and Selective Reagent for the Deprotection of Semicarbazones under Non‐Aqueous Conditions.

A variety of semicarbazones are transformed to their carbonyl compounds with quinolinium fluorochromate (QFC) in high yields under mild and non-aqueous conditions. Selective deprotection of semicarbazones and oximes in the presence of p-nitrophenylhydrazones or 2,4-dinitrophenylhydrazones is noteworthy advantage of this reagent.

Contrasting solvent effects on the kinetics of oxidation of methionine by quinolinium fluorochromate

The oxidation of methionine by quinolinium fluorochromate (QFC) has been studied, in the presence of chloroacetic acid. in water-DMSO and water-acetic acid mixtures of varying mole fractions. The reaction is first order each with respect to methionine, QFC and acid. The reaction rates have been determined at different temperatures and the activation parameters have been computed. The reaction rate increases with increase In mole fraction of acetic acid in the mixture, where the specific solvent-solvent-solute interactions were found to dominant (56%), while In water-DMSO mixtures the rate decreases with increasing mole fraction of the organic co-solvent, where the transition state was stabilized only to a lesser extent by solvation. A solvation model and a suitable mechanism for the reaction are postulated.

Quinolinium Fluorochromate: An Efficient and Selective Reagent for the Deprotection of Semicarbazones under Non-Aqueous Conditions

A variety of semicarbazones are transformed to their carbonyl compounds with quinolinium fluorochromate (QFC) in high yields under mild and non-aqueous conditions. Selective deprotection of semicarbazones and oximes in the presence of p-nitrophenylhydrazones or 2,4-dinitrophenylhydrazones is noteworthy advantage of this reagent.

Mild and Selective Oxidation of Alcohols and Deoximation of Oximes over Supported Quinolinium Fluorochromate.

Quinolinium fluorochromate supported over silica gel selectively brings about the oxidation of a wide variety of alcohols and oxidative deoximation of certain aldoximes and ketoximes to the corresponding carbonyl compounds in good yield. The reagent selectively oxidises primary hydroxyl group in the presence of secondary hydroxyl group. The selectivity is also exhibited in the oxidation of axial hydroxyl group of the cis-4-t-butyl cyclohexanol in preference to equitorial hydroxyl group. Further the reagent is stable even after a period of twelve weeks of its storage.

Quinolinium Fluorochromate as a Reagent for Selective Oxidative Cleavage of Oximes and Phenylhydrazones to Their Parent Carbonyl Compounds under Non‐Aqueous and Aprotic Conditions.

AbstractFor Abstract see ChemInform Abstract in Full Text.

An Efficient and Selective Solid State Oxidation of Thiols to Disulfides with Quinolinium Fluorochromate on Silica Gel.

Various kinds of aliphatic (cyclic and acyclic), aromatic, and heterocyclic thiols are converted into the corresponding disulfides by quinolinium fluorochromate (QFC) on silica-gel in excellent yields. Selective oxidation of thiols in the presence of sulfides is also achieved under solid phase conditions.

Selective Conversion of Thioamides and Thioureas to Their Oxygen Analogues Using Quinolinium Fluorochromate.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Kinetics and mechanism of the oxidation of DL-methionine by quinolinium fluorochromate

The oxidation of methionine (Met) by quinolinium fluorochromate (QFC) in dimethylsulphoxide (DMSO) leads to the formation of corresponding sulphoxide. The reaction is of first order with respect to QFC. Michaelis-Menten type kinetics was observed with respect to methionine. The reaction is catalysed by hydrogen ions. The hydrogen-ion dependence has the form : k o b s = a + b [H + ]. The oxidation of methionine was studied in nineteen different organic solvents. The solvent effect was analyzed by Kamlet's and Swain's multiparametric equations. Solvent effect indicated the importance of the cation-solvating power of the solvent. A suitable mechanism has also been postulated.

Quinulinium Fluorochromate C9H7NHCrO3F: An Efficient and Convenient Reagent for the Oxidative Deprotection of Trimethylsilyl Ethers in Non-Aqueous Conditions

Primary and secondary trimethylsilyl ethers are efficiently converted to their carbonyl compound using quinolinium fluorochromate in nonaqueous conditions.

Quinolinium fluorochromate as a reagent for selective oxidative cleavage of oximes and phenylhydrazones to their parent carbonyl compounds under non-aqueous and aprotic conditions

Deprotection of oximes and phenylhydrazones to their parent aldehydes and ketones in high yields has been carried out by using quinolinium fluorochromate as a selective oxidant under mild conditions.

An Efficient and Selective Solid State Oxidation of Thiols to Disulfides with Quinolinium Fluorochromate on Silica Gel

Various kinds of aliphatic (cyclic and acyclic), aromatic, and heterocyclic thiols are converted into the corresponding disulfides by quinolinium fluorochromate (QFC) on silica-gel in excellent yields. Selective oxidation of thiols in the presence of sulfides is also achieved under solid phase conditions.