scholarly journals Kinetics and Oxidation of Substituted Benzyl Alcohols by Phenyliodoso Acetate

2011 ◽  
Vol 8 (1) ◽  
pp. 264-268
Author(s):  
R. Girija ◽  
S. Aruna

Oxidation of benzyl alcohol and somemeta- andpara- substituted alcohols by phenyliodoso acetate (PIA) int-butyl alcohol–water medium (50:50) leads to the formation of corresponding benzaldehyde. The stoichiometry of the reaction was found to be 1:1. The reaction was first order each in substrate and oxidant concentrations. This reaction was studied at four different temperatures and the activation parameters were calculated. Correlation analysis was carried out using Taft’s and Swain’s dual substituent parameter (DSP) equation. The rate data ofmeta- compounds showed good correlation with (F,R) values,para-substituted benzyl alcohols showed good correlation with σIσR+A suitable mechanism has been proposed.

2003 ◽  
Vol 58 (12) ◽  
pp. 1201-1205 ◽  
Author(s):  
Hesham A. A. Medien

Quinolinium dichromate (QDC) in sulfuric acid oxidizes benzaldehydes to the corresponding acids in a 50% (v/v) acetic acid-water medium. The reaction is first order each in [QDC], [substrate] and [H+]. The reaction rates have been determined at different temperatures and the activation parameters calculated. The rate decreases with an increase in the water content of the medium. The effects of substituents have been studied. A suitable mechanism is proposed.


1971 ◽  
Vol 49 (14) ◽  
pp. 2394-2405 ◽  
Author(s):  
S. J. Dickson ◽  
J. B. Hyne

The pseudo first order rate constants for the solvolysis of benzyl chloride in aqueous t-butyl alcohol (t-BuOH) are reported at 40.00, 50.25, and 60.50 °C at various pressures up to 4084 atm. From these data the first temperature derivatives (ΔH* and ΔS*), the first (ΔV*) and second pressure derivatives, ∂ΔV*/∂P, and the mixed second derivative, ∂ΔV0*/∂T, of the rate are evaluated. These activation parameters exhibit extremum behavior in the highly aqueous solvent region. This behavior is discussed in terms of solvent structure variation. The signs of the pressure dependence of ΔH* and ΔS* are shown to be consistent with those required by the Maxwell type relationships for classical thermodynamic systems.


Author(s):  
Seplapatty Kalimuthu Periyasamy ◽  
H. Satham Hussain ◽  
R. Manikandan

The kinetics of Oxidation of Phenol and aniline by quinolinium Chlorochromate (QCC) in aqueous acetic acid medium leads to the formation of quinone and azobenzene respectively. The reactions are first order with respect to both Phenol and aniline. The reaction is first order with respect to quinolinium chlorochromate (QCC) and is catalyzed by hydrogen ion. The hydrogen-ion dependence has the form: kobs = a+b [H+]. The rate of oxidation decreases with increasing dielectric constant of solvent, indicating the presence of an ion-dipole interaction. The reaction does not induced the polymerization of acrylonitrile. The retardation of the rate by the addition of Mn2+ ions confirms that a two electron transfer process is involved in the reaction. The reaction rates have been determined at different temperatures and the activation parameters have been calculated. From the above observations kinetic results a probable mechanism have been proposed.


2001 ◽  
Vol 56 (3) ◽  
pp. 281-286 ◽  
Author(s):  
Ceyhan Kayran ◽  
Eser Okan

Abstract The kinetics of the thermal substitution of norbornadiene (nbd) by 2,2'-bipyridine (2,2'-bipy) in (CO)4Mo(C7H9) was studied by quantitative FT-IR and UV-VIS spectroscopy. The reaction rate exhibits first-order dependence on the concentration of the starting complex, and the observed rate constant depends on the concentration of both leaving nbd and entering 2,2'-bipy ligand. The mechanism was found to be consistent with the previously proposed one, where the rate determining step is the cleavage of one of the two Mo-olefin bonds. The reaction was performed at four different temperatures (35 -50 °C) and the evaluation of the kinetic data gives the activation parameters which now support states.


2016 ◽  
Vol 12 (9) ◽  
pp. 4396-4403 ◽  
Author(s):  
K Anbarasu ◽  
N. GEETHA

The kinetics and mechanism of oxidation of benzaldehyde by quinoxalinium dichromate has been studied in the presence of perchloric acid in 70 % acetic acid - water medium. The reaction follows first order with respect to benzaldehyde, quinoxalinium dichromate and fractional order with respect to perchloric acid. There is no effect on the reaction rate with increase in ionic strength of the medium by adding sodium perchlorate. The rate of reaction increases with increase in the percentage of acetic acid. The reaction does not induce the polymerization with acrylonitrile. The rate of reaction decreases with increase in the concentration of manganoussulphate. The thermodynamic and activation parameters have been calculated and a probable mechanism has been proposed.


2019 ◽  
Author(s):  
Chem Int

Kinetic and thermodynamic investigation on Os(VIII) catalysed oxidation of glycine by ferrate(VI) has been done in basic medium and in the temperature range 30– 450C. Rate of oxidation increases with increase in [FeO4]2- and [Os(VI)] and shows first order dependence. Rate of oxidation also increases with the increase in [S] but order is fractional. The rate decreases with an increase in pH. Rate of reaction is independent of [KCl], [KNO3] and change in ionic strength. The values of rate constant observed at four different temperatures were used to calculate the activation parameters. The energy of activation (ΔE*) of the reaction at pH 11 and temperature 350C was found to be 49.56 kJmol-1. [OsO4(H2O)2] and [FeO42−] are proposed to be the reactive species of Os(VIII) and Fe(VI) respectively in the present investigation. Formaldehyde is found to be main product of the reaction along with carbon dioxide and ammonia as by products. On the basis of experimental findings, a suitable mechanism consistent with the observed kinetics is proposed and a rate law has been derived on the basis of obtained data.


1992 ◽  
Vol 70 (10) ◽  
pp. 2515-2519 ◽  
Author(s):  
Sharifa S. Alkaabi ◽  
Ahmad S. Shawali

The kinetics of the reactions of a series of (Z)-4-arylidene-2-phenyl-5(4H)oxazolones 1 with n-butylamine and piperidine were studied spectrophotometrically in dioxane, ethanol, and cyclohexane under pseudo-first-order conditions and at different temperatures. The relation k1(obs) = k2[amine] + k3[amine]2 was found applicable for all reactions studied in either dioxane or ethanol. However, in cyclohexane the n-butylaminolysis of 1 followed only third-order kinetics k1(obs) = k3[n-BuNH2]2. The kinetics of the reaction of 1 with n-butylamine in the presence of catalytic amounts of triethylamine in dioxane followed the equation: k1(obs)k2 = [n-BuNH2] + k3[n-BuNH2]2[Formula: see text] [Et3N]. The rate constants k2 and k3 correlated well with the Hammett equation and the corresponding activation parameters were determined. The results were interpreted in terms of a mechanism involving solvent- and amine-catalyzed processes.


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