Copper(II) and nickel(II) complexes with oxime analogues of amino acids. Potentiometric, spectroscopic and X-ray studies of complexes with 2-cyano-2-(hydroxyimino)acetic acid and its ethane-1,2-diamine derivative

Abstract

2-Cyano-2-(hydroxyimino)acetic acid was found to be an effective ligand for Cu²⁺ and Ni²⁺ ions over a very broad pH range. Potentiometric and spectroscopic data indicate the formation of dimeric complexes with Cu²⁺ ions and the first X-ray evidence for dimer formation is obtained. Conjugation of the oximic moiety with ethane-1,2-diamine leads to another very effective family of chelating agents, although metal ion co-ordination may induce amide bond hydrolysis as indicated by the crystal structure.

References

1. Ch. O. Onindo, T. Yu. Sliva, T. Kowalik-Jankowska, I. O. Fritsky, P. Buglyo, L. D. Pettit, H. Kozlowski and T. Kiss, J. Chem. Soc., Dalton Trans., 1995, 3911.
2. T. Yu. Sliva, A. M. Duda, T. Glowiak, I. O. Fritsky, V. M. Amirkhanov, A. A. Mokhir and H. Kozlowski, J. Chem. Soc., Dalton Trans., 1997, 273.
3. T. Yu. Sliva, T. Kowalik-Jankowska, V. M. Amirkhanov, T. Glowiak, Ch. O. Onindo, I. O. Fritsky and H. Kozlowski, J. Inorg. Biochem., 1997, 65, 287.
4. A. M. Duda, A. Karaczyn, H. Kozlowski, I. O. Fritsky, T. Glowiak, E. V. Prisyazhnaya, T. Yu. Sliva and J. Swiatek-Kozlowski, J. Chem. Soc., Dalton Trans., 1997, 3853.
5. V. Yu. Kukushkin, D. Tudela and A. J. L. Pombeiro, Coord. Chem. Rev., 1996, 156, 333.
6. P. Gans, A. Sabatini and A. Vacca, J. Chem. Soc., Dalton Trans., 1985, 1195.
7. Kuma KM4 software, User's Guide, Version 6.1, Kuma Diffraction, Wrocław, 1996.
8. N. Walker and D. Stuart, Acta Crystallogr., Sect. A, 1983, 39, 158.
9. G. M. Sheldrick, Acta Crystallogr., Sect. A, 1990, 46, 467.
10. G. M. Sheldrick, SHELXL 93, Program for the Refinement of Crystal Structures, University of Göttingen, 1994.
11. L. D. Pettit, J. E. Gregor and H. Kozlowski, in Perspectives on Bioinorganic Chemistry, eds. R. W. Hay, J. R. Dilworth and K. B. Nolan, JAI Press, London, 1991, p. 1.