scholarly journals Meso-tetraphenylporphyriniron(iii) chloride catalyzed oxidation of aniline and its substituents by magnesium monoperoxyphthalate in aqueous acetic acid medium

2012 ◽  
Vol 14 (4) ◽  
pp. 35-41 ◽  
Author(s):  
Raja Manickam ◽  
Karunakaran Kulandaivelu

Abstract The catalytic properties of the first generation catalyst meso-tetraphenylporphyriniron(III) chloride and magnesium monoperoxyphthalate (MMPP) as oxidant have been studied in the oxidation of aniline and its substituents in acetic acid medium. The thermodynamic parameters for the oxidation have been determined and discussed. It confirms the Exner relationship (only at the low range of temperatures) and also some of the activation parameters to the isokinetic relationships. The magnesium monoperoxyphthalate oxidation with 18 ortho- meta- and para-substituted anilines fulfills with isokinetic relationship but not to any of the linear free energy relationships. The reaction mechanism and the rate law were proposed.

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
S. Shree Devi ◽  
B. Muthukumaran ◽  
P. Krishnamoorthy

Kinetics and mechanism of oxidation of substituted 5-oxoacids by sodium perborate in aqueous acetic acid medium have been studied. The reaction exhibits first order both in [perborate] and [5-oxoacid] and second order in [H+]. Variation in ionic strength has no effect on the reaction rate, while the reaction rates are enhanced on lowering the dielectric constant of the reaction medium. Electron releasing substituents in the aromatic ring accelerate the reaction rate and electron withdrawing substituents retard the reaction. The order of reactivity among the studied 5-oxoacids is p-methoxy ≫ p-methyl > p-phenyl > –H > p-chloro > p-bromo > m-nitro. The oxidation is faster than H2O2 oxidation. The formation of H2BO3+ is the reactive species of perborate in the acid medium. Activation parameters have been evaluated using Arrhenius and Eyring’s plots. A mechanism consistent with the observed kinetic data has been proposed and discussed. Based on the mechanism a suitable rate law is derived.


2004 ◽  
Vol 1 (2) ◽  
pp. 127-131 ◽  
Author(s):  
N. A. Mohamed Farook ◽  
R. Prabaharan ◽  
S. Rahini ◽  
R. Senthil Kumar ◽  
G. Rajamahendran ◽  
...  

The kinetics of oxidation of some amino acids namely, glycine, alanine, aspartic acid, arginine, and histidine, (AA) byN-chlorosaccharin (NCSA) in aqueous acetic acid medium in the presence of perchloric acid have been investigated. The observed rate of oxidation is first order in [AA], [NCSA] and of inverse fractional order in [H+]. The main product of the oxidation is the corresponding aldehyde. The ionic strength on the reaction rate has no significant effect. The effect of changing the dielectric constant of the medium on the rate indicates the reaction to be of dipole-dipole type. Hypochlorous acid has been postulated as the reactive oxidizing species. The reaction constants involved in the mechanism are derived. The activation parameters are computed with respect to slow step of the mechanism.


Author(s):  
S. Parimala Vaijayanthi ◽  
N. Mathiyalagan

The kinetics of oxidation of amino acids namely, alanine, glycine, leucine, phenyl alanine and valine by N-chloropyrazinamide (NCPZA) in aqueous acetic acid medium in the presence of hydrochloric acid have been investigated. The observed rate of oxidation is first order in [NCPZA], [H+] and [Clˉ]. The order with respect to [amino acid] is zero. The rate of oxidation increases with increase in the percentage of acetic acid. The reaction rate increases slightly with increase in ionic strength, while retards with addition of pyrazinamide. Arrhenius and thermodynamic activation parameters have been evaluated from Arrhenius plot by studying the reaction at different temperatures. A most probable reaction mechanism has been proposed and an appropriate rate law is deduced toaccount for the observed kinetic data.


2004 ◽  
Vol 3 (1) ◽  
pp. 1-6
Author(s):  
R. Sridharan ◽  
N. Mathiyalagan

Kinetics of oxidation o Cyclohexanol by N-Chloronicotinamide(NCN) in 50% V/V aqueous acetic acid mixture has been investigated in the presence of HCIO4 and NaCl. The observed rate of oxidation is first-order with respect to oxidation (NCN) and fractional-order with respect to cyclohexanol. A decrease in dielectric constant of the medium increases the rate. Addition of nicotinamide (NA), the reduction product of NCN, has a retarding effect an the rate of oxidation. Arrhenius and activation parameters are calculated. Kinetics of bromination1 and oxidation2,3 of saturated organic compounds by N-bromosuccinimide(NBS) have been received considerable attention. Kinetics and mechanism of oxidation of amino acids by NCN has been reported in aqueous acetic acid medium, we report herein the result of similar studies on the oxidation of cyclohexanol with NCN in aqueous acetic acid medium.


2011 ◽  
Vol 8 (2) ◽  
pp. 561-564 ◽  
Author(s):  
N. A. Mohamed Farook ◽  
G. A. Seyed Dameem

The kinetics of oxidation of 3-benzoylpropionic acid(KA)byN-chlorobenzamide(NCB)in aqueous acetic acid medium in the presence of perchloric acid have been investigated. The observed rate of oxidation is first order dependence each in[KA],[NCB]and [H+]. The main product of the oxidation is the corresponding carboxylic acid. The rate decreases with the addition of benzamide, one of the products of the reaction. Variation in ionic strength of the reaction medium has no significant effect on the rate of oxidation. But the rate of the reaction is enhanced by lowering the dielectric constant of the reaction medium. Hypochlorous acidium ion (H2O+Cl), has been postulated as the reactive oxidizing species. A mechanism consistent with observed results have been proposed and the related rate law deduced. The activation parameters have been computed with respect to slow step of the mechanism.


2009 ◽  
Vol 6 (s1) ◽  
pp. 522-528 ◽  
Author(s):  
S. Sheik Mansoor ◽  
S. Syed Shafi

The kinetics of oxidation of benzaldehyde (BA) andpara-substituted benzaldehydes by imidazolium dichromate (IDC) has been studied in aqueous acetic acid medium in the presence of perchloric acid. The reaction is first order each in [IDC], [Substrate] and [H+]. The reaction rates have been determined at different temperatures and the activation parameters calculated. Electron withdrawing substituents are found to increase the reaction and electron releasing substituents are found to retard the rate of the reaction and the rate data obey the Hammett relationship. The products of the oxidation are the corresponding acids. The rate decreases with the increase in the water content of the medium. A suitable mechanism is proposed.


2005 ◽  
Vol 60 (10) ◽  
pp. 1105-1111 ◽  
Author(s):  
Durvas S. Bhuvaneshwari ◽  
Kuppanagounder P. Elango

The nicotinium dichromate (NDC) oxidation of anilines, in varying mole fractions of benzene/2- methylpropan-2-ol mixtures, in the presence of p-toluenesulfonic acid (TsOH) is first order in NDC and TsOH and zero order with respect to anilines in the concentration range investigated. The NDC oxidation of 15 meta- and para-substituted anilines complies with the isokinetic relationship but not to any of the linear free energy relationships. The activation free energy data failed to correlate with macroscopic solvent parameters such as εr and ENT. Correlation of ΔG# with Kamlet-Taft solvatochromic parameters (α, β , π*) suggests that the specific solute-solvent-solvent interactions play a major role in governing the reactivity.


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