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Babu, B. Suresh
- Kinetic and mechanistic studies of cerium(III)-catalysed oxidation of 4-oxo acids by bromate in acid medium: nonlinear Hammett plots
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Authors
Affiliations
1 Department of Chemistry, University College, Kakatiya University, Warangal 506 009, IN
2 Department of Chemistry, University College of Science, Saifabad, Osmania University, Hyderabad 500 004, IN
1 Department of Chemistry, University College, Kakatiya University, Warangal 506 009, IN
2 Department of Chemistry, University College of Science, Saifabad, Osmania University, Hyderabad 500 004, IN
Source
Current Science, Vol 121, No 5 (2021), Pagination: 651-659Abstract
The kinetic and mechanistic aspects of cerium(III)-catalysed oxidation of 4-oxo acids by bromate (uncontaminated with bromine) in an acid medium have been studied. The reaction exhibited first-order each in [bromate] and [acid], fractional order each in [oxo acid] and [cerium(III)], and also showed solvent isotope effect of 0.55 ( κ(H2O)/ κ (D2O)). The reaction did not induce polymerization and the induction period was not observed. The influence of ionic strength on the rate was negligible, while increase in reaction rate was found by lowering the dielectric constant of the medium. The reaction rate was affected by the presence of substituents in the reaction centre. Increase in the reaction rate by electron releasing substituents and decrease in the rate by the presence of electron-withdrawing substituents were observed. The Hammett plots were characterized by smooth curvature; however, linearity was observed using exalted σ values. A negative value for the reaction constant was observed. The isokinetic relationship was evaluated from the Arrhenius and Hammett plots. The formation of a ternary complex between oxidant, substrate and catalyst has been proposed in the mechanism. Based on the proposed mechanism, the rate law has been derived. The formation of a π-complex between Ce(III) and -ene of the enol form of oxo acid has been proposed. This reaction finds application in the synthesis of substituted benzoic acids and involves the phenomena of intramolecular catalysis and neighbouring group participation.Keywords
Bromate oxidation, cerium(III) catalysis, isokinetic relationships, reaction mechanism, 4-oxo acids.Full Text
References
- Fuentes, L. M., Gerald, L. and Larson, G. L., A facile synthesis of 4-oxo carboxylic acids from γ-butyrolactone. Tetrahedron Lett., 1982, 23(3), 271–274.
- Bell, R. B. and Covington, D., Intra- and inter-molecular catalysis in the halogenation of some oxocarboxylic acids. J. Chem. Soc., Perkin Trans 2, 1975, 12, 1343–1348.
- Bhatt, M. V., Ravindranathan, M., Somayaji, V. and Rao, G. V., Aspects of tautomerism. 13. Alkaline hydrolysis of gamma-, deltaand epsilon-keto esters and their desoxy analogs. Geometrical constraints on keto participation. J. Org. Chem., 1984, 49(17), 3170–3173.
- Kavitha, S., Pandurangan, A. and Alphonse, I., Kinetics and mechanism of oxidation of beta benzoylpropionic acids by pyridinium fluoro-chromate in aqueous acetic acid medium. Indian J. Chem. A, 2005, 44(4), 715–718.
- Farook, N. A. M., Kinetics and mechanism of oxidation of 4oxoacids by N-bromosuccinimide in aqueous acetic acid medium. J. Iran. Chem. Soc., 2006, 3, 378–386.
- Vannamuthu, I., Saleem Malik, V., Shafi, S. and Sheik Mansoor, S., Kinetics and mechanism of oxidation of 4-oxo-4-phenyl butanoic acid by benzimidazolium fluorochromate in presence of 1,10-phenthroline catalyst in acetic acid–water medium. Der Pharm. Lett., 2015, 7(3), 96–103.
- Kudzanai Chipiso, A. and Simoyi, R. H., Kinetics and mechanism of oxidation of d-penicillamine in acidified bromate and aqueous bromine. Aust. J. Chem., 2016, 69, 1305–1313.
- Olagunju, O. and Simoyi, R. H., Oxyhalogen–sulfur chemistry: kinetics and mechanism of oxidation of 1,3-dimethylthiourea by acidic bromate. J. Phys. Chem. A, 2017, 12, 6366–6376.
- Field, R. J., Koros, E. and Noyes, R. M., Oscillations in chemical systems. II. Thorough analysis of temporal oscillation in the bromate–cerium–malonic acid system. J. Am. Chem. Soc., 1972, 94(25), 8649–8644.
- Noyes, R. M., Chemical oscillations and instabilities. 39. A generalized mechanism for bromate-driven oscillators controlled by bromide. J. Am. Chem. Soc., 1980, 102(14), 4644–4649.
- Hegedus, L., Wittmann, M., Noszticzius, Z., Van, S., Sirimungkala, A., Forsterling, H. D. and Field, R. J., HPLC analysis of complete BZ systems. Evolution of the chemical composition in cerium and ferroin catalysed batch oscillators: experiments and model calculations. Faraday Discuss., 2002, 120, 21–38, and references therein.
- Karunakaran, Ch. and Chidambaranathan, V., Linear free energy relationships near isokinetic temperature. Oxidation of organic sulfides with nicotinium dichromate. Croat. Chem. Acta, 2001, 74(1), 51–59.
- Jeffery, J. H., Bassett, J., Mendham, J. and Denney, R. C., Vogel’s Textbook of Quantitative Chemical Analysis, ELBS, Longman, Essex, UK, 1996, 5th edn, p. 843.
- Bailer, J. C., The Chemistry of Coordination Compounds, Reinhold, New York, USA, 1956, p. 787.
- Fiegl, F. and Anger, V., Spot Tests in Organic Analysis, Elsevier, Amsterdam, The Netherlands, 1975, p. 459.
- Brown, H. C. and Okamoto, Y., Electrophilic substituent constants. J. Am. Chem. Soc., 1958, 80(18), 4979–4987.
- Yoshida, T. and Ushiki, Y., The kinetics of bromate–cerium(III) and –iron(II) reactions. Bull. Chem. Soc. Jpn, 1982, 55(6), 1772– 1776.
- Rabai, G. and Hanazaki, I., pH Oscillations in the bromate– sulfite–marble semibatch and flow systems. J. Phys. Chem., 1996, 100(25), 10615–10619.
- Krishnan, S. V. and Santappa, M., Oxidation of acetone and methylethyl ketone by ceric ions in aqueous solution. Z. Phys. Chem., 1958, 16, 73–84.
- Sanjeeva Reddy, Ch. and Sunitha Manjari, P., Homogeneous catalysis of oxovanadium(IV) in the oxidation of substituted 4-oxoacids by bromate in acid medium: a mechanistic study. J. Mol. Catal A:Chem., 2010, 328, 76–87.
- Nathan, W. S. and Waston, H. B., Constitutional factors controlling prototropic changes in carbonyl compounds. Part III. The prototropy of nuclear-substituted acetophenones. J. Chem. Soc., 1933, 217–220.
- Sunitha Manjari, P. and Sanjeeva Reddy. Ch., Aquachlororuthenium(III) catalysis in theoxidation of substituted 4-oxo-4-arylbutanoic acids by bromatein acid medium: a kinetic and mechanistic study and validity of linear free-energy relationships. Trans. Met. Chem., 2011, 36(7), 707–719.
- Tsurugi, H. and Mashima, K., Renaissance of homogeneous cerium catalysts with unique Ce(IV/III) couple: redox-mediated organic transformations involving homolysis of Ce(IV)–ligand covalent bonds. J. Am. Chem. Soc., 2021; article ASAP, doi:10.1021/jacs.1c02889.
- Sanjeeva Reddy, Ch. and Sundaram, E. V., Mechanism of acid bromate oxidation of trans mono-substituted cinnamic acids: structure reactivity correlation – a non-linear Hammett’s plot. Tetrahedron., 1989, 45(7) 2109–2126.
- Exner, O., Entropy–enthalpy compensation and anti-compensation: solvation and ligand binding. Chem. Commun., 2000, 17, 1655–1656.
- Schmid, R. and Sapunov, V. N., Non-Formal Kinetics, Monograph in Modern Chemistry (ed. Ebel, H. F.), Verlag Chemie, Weinheim, 1982, p. 21.