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Ruthenium(III) – catalyzed oxidative cleavage of p-aminoazobenzene by chloramine-B in alkaline medium and uncatalyzed reaction in acid medium: spectrophotometric kinetic and mechanistic study

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p-Aminoazobenzene (PAAB) is one of the important monoazo dyes and its oxidation kinetic study is of much use in understanding the mechanistic profile of PAAB in redox reactions. Consequently, the kinetics of oxidation of PAAB by sodium N-chlorobenzenesulfonamide or chloramine-B (CAB) in HClO4 medium and in NaOH medium catalyzed by ruthenium(III) chloride (RuIII) have been investigated at 298 K. U.v.–vis spectrophotometry was used as a basic analytical approach in this study. Under an identical set of experimental conditions, the reactions of PAAB–CAB in HClO4 medium were facile, but the reactions became too slow to be studied in alkaline medium and hence ruthenium(III) chloride has been used as a catalyst in alkaline medium. The stoichiometry (1:2) and oxidation products (nitrosobenzene and p-nitrosoaniline) are the same in both media, but the kinetic and mechanistic patterns were found to be different. The experimental rate laws obtained are: − d[CAB]/dt = k [CAB]0 [PAAB]0 [H+] in acid medium and − d[CAB]0/dt = k [CAB]0 [PAAB]0[OH]x[RuIII]y in alkaline medium, where x and y are less than unity. The reaction was examined with reference to changes in (a) concentration of benzenesulfonamide, (b) concentration of added neutral salts, (c) ionic strength, (d) dielectric permitivity and (e) solvent isotope effect. The reaction was also studied at different temperatures and the overall activation parameters have been evaluated. The oxidation reaction fails to induce the polymerization of added acrylonitrile. C6H4SO2NHCl and C6H4SO2NCl have been postulated as the reactive oxidizing species in acidic and alkaline media, respectively. It was found that the reactions are nearly 20 times faster in acid medium in comparison with alkaline medium. It was also observed that ruthenium(III) was an efficient catalyst for the facile oxidation of PAAB by CAB in alkaline medium by making the reaction go twelve-fold faster than the uncatalyzed reactions. The catalytic constant (K C) has been calculated at different temperatures and the values of activation parameters with respect to ruthenium(III) have also been evaluated in alkaline medium. The observed results have been explained by plausible mechanisms and the relative rate laws have been deduced.

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  1. 1.

    Zollinger H. (1981). Color Chemistry: Syntheses, Properties and Applications of Organic Dyes and Pigments. VCH, New York, 92

  2. 2.

    Campbell M.M. and Johnson G. (1978). Chem. Rev. 78: 65

  3. 3.

    Bishop E. and Jennings V.J. (1958). Talanta 1: 197

  4. 4.

    Banerji K.K., Jayaram B. and Mahadevappa D.S. (1987). J. Sci. Ind. Res. 46: 65

  5. 5.

    Bremner D.H. (1985). Synth. Reagents 6: 9

  6. 6.

    Hardy F.F. and Johnston J.P. (1973). J. Chem. Soc. Perkin Trans. 2: 742

  7. 7.

    Meenakshisundaram S.P. and Sockalingam R. (2000). J. Mol. Catal A: Chem. 160: 269

  8. 8.

    Puttaswamy, Anuradha T.M., Ramachandrappa R. and Gowda N.M.M. (2000). Int. J. Chem. Kinet. 32: 221

  9. 9.

    Gowda B.T., Damodara N. and Jyothi K. (2005). Int. J. Chem. Kinet. 37: 572

  10. 10.

    Puttaswamy, Jagadeesh R.V. (2005). Cent. Eur. J. Chem. 3: 482

  11. 11.

    Srivastava S.H., Singh K., Shukla M. and Pandey N. (2001). Oxid. Commun. 24: 558 and references therein

  12. 12.

    Bhat K.R., Jyothi K. and Gowda B.T. (2002). Oxid. Commun. 25: 117

  13. 13.

    Verger J. and Perlin C. (1967). Chem. Abstr. 66: 79665

  14. 14.

    Puttaswamy, Mahadevappa D.S. and Rangappa K.S. (1989). Bull. Chem. Soc. Jpn. 62: 3343

  15. 15.

    Akerloff G. (1932). J. Chem. Soc. 54: 4125

  16. 16.

    Morris J.C., Salazar J.A. and Wineman M.A. (1948). J. Am. Chem. Soc. 70: 2036

  17. 17.

    B.G. Pryde, F.G. Soper, J. Chem. Soc., 1582 (1962).

  18. 18.

    Laidler K.J. (1965). Chemical Kinetics. Tata-McGraw-Hill, Mumbai, India, 227

  19. 19.

    Deliyannis A.P. (1957). Chim. Chronika Athens 22: 22

  20. 20.

    Spacu P. and Dumitrescu H. (1970). An. Univ. Bucaresti Chim. 19: 17

  21. 21.

    Collins C.J. and Bowman N.S. (1970). Isotope Effects in Chemical Reactions. Van-Nostrand Reinhold, New York, 267

  22. 22.

    Wieberg K.B. (1955). Chem. Rev. 55: 712

  23. 23.

    Puttaswamy, Jagadeesh R.V. (2005). Int. J. Chem. Kinet. 37: 201

  24. 24.

    Puttaswamy, Vaz N. (2003). Transition Met. Chem. 28: 409

  25. 25.

    Ananda S., Demappa T., Puttaswamy and Gowda N.M.M. (2000). Transactions Illi. State Acad. Sci. 93: 25

  26. 26.

    Cady H.H. and Connick R.E. (1958). J. Am. Chem. Soc. 80: 2646

  27. 27.

    Connick R.E. and Fine D.A. (1960). J. Am. Chem. Soc. 82: 4187

  28. 28.

    Cotton F.A., Wilkinson G., Murillo C.A. and Bochmann M. (1999). Advanced Inorganic Chemistry, 4th Edn. Wiley, New York

  29. 29.

    Balado A.M., Galam B.C. and Martin F.J.P. (1992). Anal. Quim. 88: 170

  30. 30.

    Radhakrishnamurthy P.S. and Panday H.P. (1980). Bull. Soc. Kinet. Ind. 2: 6

  31. 31.

    Kamble D.L. and Nandibewoor S.T. (1998). J. Phys. Org. Chem. 11: 171

  32. 32.

    Amis E.S. (1966). Solvent Effects on Reaction Rates and Mechanisms. Academic Press, New York

  33. 33.

    Moelwyn-Hughes E.A. (1947). Kinetics of Reactions in Solutions. Oxford University Press, London, 297

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Puttaswamy, Shubha, J.P. & Jagadeesh, R.V. Ruthenium(III) – catalyzed oxidative cleavage of p-aminoazobenzene by chloramine-B in alkaline medium and uncatalyzed reaction in acid medium: spectrophotometric kinetic and mechanistic study. Transition Met Chem 32, 991–999 (2007). https://doi.org/10.1007/s11243-007-0271-x

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  • Ruthenium
  • Alkaline Medium
  • HOCl
  • Benzenesulfonamide
  • Uncatalyzed Reaction