Interaction of 2-amino-N-hydroxypropanamide with vanadium(V) in aqueous solution

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Regina T. Yamaki, Eucler B. Paniago, Sandra Carvalho and Ivana S. Lula


Abstract

The equilibria between vanadium(V) and 2-amino-N-hydroxypropanamide (HL or β-alaninehydroxamic acid, NH2CH2CH2CONHOH) in aqueous solution have been studied at 25 °C in 0.10 mol dm–3 NaClO4 medium by combined potentiometric, spectrophotometric and 51V NMR methods. Complexes are formed between VO2+ and the β-alaninehydroxamate anion (L) in the pH range 2.5–10.5, and many of their formation constants have been determined. Complexes with a 1∶1 and 2∶1 ligand∶metal ratio, depending on pH, can be either protonated or deprotonated, forming positively charged, neutral or negatively charged species: [VO2HL]+ and [VO2H3L2]2+ coexist below pH 3.5, with [VO2HL]+ predominating over [VO2H3L22+]. From pH 3.5 to 7.0 the main species are [VO2H2L2]+ and, to a lesser extent, [VO2L]. Above pH 7, [VO2H2L2]+ deprotonates to form [VO2HL2] and [VO2L2]. Above pH 9.5, the prevailing complex species are [VO2H–1L] and [VO2H–2L]2–, being finally replaced by HVO42– above pH 10.5.


References

  1. H. Sigel and A. Sigel(Editors), in Metal Ions in Biological Systems, Marcel Dekker, New York, 1995, vol. 31 Search PubMed.
  2. M. Fritzsche, V. Vergopoulos and D. Rehder, Inorg. Chim. Acta, 1993, 211, 11 CrossRef CAS.
  3. K. Elvingson, M. Fritzsche, D. Rehder and L. Pettersson, Acta Chem. Scand., 1994, 48, 878 CrossRef CAS.
  4. K. Elvingson, A. G. Baró and L. Pettersson, Inorg. Chem., 1996, 35, 3388 CrossRef CAS.
  5. E. Lipczynska-Kochany, Chem. Rev., 1991, 91, 477 CrossRef CAS.
  6. B. Kurzak, H. Kozlowski and E. Farkas, Coord. Chem. Rev., 1992, 114, 169 CrossRef CAS.
  7. E. B. Paniago and S. Carvalho, Ciênc. Cult., 1988, 40, 629 Search PubMed.
  8. R. T. Yamaki, E. B. Paniago, S. Carvalho, O. W. Howarth and W. Kam, J. Chem. Soc., Dalton Trans., 1997, 4817 RSC.
  9. H. A. Duarte, E. B. Paniago, S. Carvalho and W. B. de Almeida, J. Inorg. Biochem., 1998, 72, 71 CrossRef CAS.
  10. E. Farkas, T. Kiss and B. Kurzak, J. Chem. Soc., Perkin Trans. 2, 1990, 1255 RSC.
  11. F. J. C. Rossotti and H. Rossotti, Acta Chem. Scand., 1956, 10, 957 CAS.
  12. P. Gans, A. Sabatini and A. Vacca, J. Chem. Soc., Dalton Trans., 1985, 1195 RSC.
  13. E. B. Paniago, H. A. Duarte, F. F. Campos Filho, S. Carvalho and B. R. G. M. Couto, in Congresso Latino Americano de Química 19 ( 1990), Anais., Buenos Aires, 1990, p. P1528.
  14. E. B. Paniago, H. A. Duarte and F. F. Campos Filho, Quím. Nova, 1994, 17, 5, 397 Search PubMed.
  15. H. Thiele, A. Germanus, R. Paape and P. Krygsman, Manual 1D WIN-NMR, Bruker, 1994 Search PubMed.