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Kinetic Study of Oxidation of Acettyl Acetone by
Nicotinium Dichromate
S.K. NIGAM#, PRIYANKA PATEL*, AKS TIWARI# and ANITA TIWARI#
Govt. Tilak PG College, Katni, M.P., INDIA. Govt. Model Science College, Rewa, M.P., INDIA. ABSTRACT

The oxidation of active methylene group has been carried out with
Nicotinium dichromate (3-carboxy pyridium, NDC) in acetic acid
medium in the presence of H+ ion. It is found that rate is a direct
function of first power concentration of oxidant i.e. NDC and zero
order with respect to substrate i.e. active methylene compound.
The reaction was found to increase with increase. concentration of
acid. The reactive species is H2CrO4.
Keywords: Oxidimetric, Degradation, Nicotinium dichromate.
INTRODUCTION
pyridium NDC is a titrant for the oxidimetric heterocyclic bases is a mild oxidant, soluble in organic solvent and used under anhydrous NDC for the first time as an oxidant for the compounds in aqueous acetic acid medium. Oxidation of active methylene compound is phosphoric acid (PMPA)4, Ce(IV)5, Mn (II)6, common and the oxidation is first order with Nano Vision, Vol.3, Issue 2, 30 June, 2013, Pages (44-92) S. K. Nigam, et al., Nano Vision, Vol.3 (2), 70-74 (2013) both being equilibrated in a thermostatic iodometrically. The duplicate kinetic runs EXPERIMENT
showed reproducible results of rate constant RESULT AND DISCUSSION
substrate was prepared in purified glacial acetic acid-water mixture as required. The that for complete oxidation of 3 moles of standard solution of NDC was obtained by mole of NDC is required. The product of the 100% acetic acid. The standardization is oxidation was ascertained by the formation of 2, 4-diphenyl hydrazone (DNP) using 2, 4-dinitrophenyl hydrazine8.The kinetic data made under pseudo first order condition by have been collected for 5 fold concentration maintaining (substrate) >> (oxidant). The of oxidant (NDC) at fixed concentration of reaction was initiated by adding requisite other reactants and temperature. The linear amount of solution of substrate to the NDC plot of log a/(a-x) vs. time shows the first- solution containing acetic acid and water order rate dependency with respect to NDC. [A.A.] = 1.25 ×10-2 (mol.dm-3), [NDC] = 2.50 ×10-3 (mol.dm-3), [H+] = 1.25 ×10-3 (mol.dm-3), HOAc-H2O =15 % (v/V), Temp. = 308 K Nano Vision, Vol.3, Issue 2, 30 June, 2013, Pages (44-92) S. K. Nigam, et al., Nano Vision, Vol.3 (2), 70-74 (2013) Table: 1 Typical kinetic run for the effect of Nicotinium dichromate
Kinetics of oxidation reaction between acetyl acetone with NDC kinetics with respect to substrate at lower concentration and tends toward zero-order at higher concentration. The evidence indicates reaction is fully acid catalyzed and first- the formation of complex during the reaction order with respect to acid concentration Fig. between each substrate and oxidant. The plot Fig. II: [A.A.] = 1.25 ×10-2 (mol.dm-3), [NDC] = 2.50 ×10-3 (mol.dm-3),
[H+] = 2.00 ×10-3 (mol.dm-3), HOAc-H2O = 15 % (v/V), Temp. = 308 0k. Nano Vision, Vol.3, Issue 2, 30 June, 2013, Pages (44-92) S. K. Nigam, et al., Nano Vision, Vol.3 (2), 70-74 (2013) Table: 2 Typical kinetic run for the effect of Sulphuric acid
Kinetics of oxidation reaction between acetyl acetone with NDC = 2.00 ×10-3 (mol.dm-3), HOAc-H2O = 15 % (v/V),Temp.=308K with increasing chromic acid concentration. acetic acid and water binary mixture. It was percentage composition i.e. content of acetic equilibrium will shift to the left and hence acid in the reaction mixture. Since the plot of log k1 vs. 1/D is linear with positive slop. 2CrO4. This concludes that H2CrO4 is the oxidizing species in the oxidation of active not alter the rate of reaction. This shows that rate determining step involves either neutral species or an ion and a neutral molecule. Mechanism
The study rules out the formation of any free radical by the addition of acrylonitrile. oxidation of active methylene compounds in species since the rate of the reaction increase Nano Vision, Vol.3, Issue 2, 30 June, 2013, Pages (44-92) S. K. Nigam, et al., Nano Vision, Vol.3 (2), 70-74 (2013) (Oxidant product)


Where, R and R’ = -CH3 for Acetyl acetone; R = -C6H5 and R’ = -CH3 for Benzoyl acetone; R = -CH2NO2 and R’ = -CH3 for Nitro acetyl acetone. The above mechanism leads to the following rate law.
REFERENCES
Panigrahi, Radhashyam S, Panda: Bull. Soc. Jpn.60.3391-3395(Sept.1997). 1. G. Cainelli and G. Cardillio, Chromium 5. R.K. Prasad, S.N.Tripathi: Indian J. Springer-Verlage, Berline, pp. 40-258 6. M. Mrakavova, and L. Treindal: Chem., (1984). 7. F.G. mann and B.C. Sunders : Practical and Palomo: Synth, Commun.15,1197- 8. N. Bjerrum :Z.Phy.Chem.,82,108(1924). and Puttaswami: Proc. Indian Acad. Sci. 9. J.N. Bronsted : J. Phy. Chem. 102, 169 (Chem. Sci.) Vol. 104, No.PP. 611-618 10. J.P. Sewanee, Anita Valechha: J. Indian 4. Chakrapani P., S.N. Mahapatta, Akhil K. Nano Vision, Vol.3, Issue 2, 30 June, 2013, Pages (44-92)

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