Copper(II) complexes of mono- and di-nucleating hexaamines †

Abstract

The potentially hexadentate polyamines N,N,N′,N′-tetrakis(2-aminoethyl)ethane-1,2-diamine (L¹) and the octamethylated analogue N,N,N′,N′-tetrakis(2-dimethylaminoethyl)ethane-1,2-diamine (L²) have been complexed with copper(II) and the crystal structures of their complexes determined. A trigonal-bipyramidal co-ordination geometry for [Cu(HL¹)][ClO₄]₃ was found where one aminoethyl arm is not co-ordinated. By contrast, a dinuclear structure of formula [(H₂O)Cu(L²)Cu(OH)]³⁺ was determined for the N-methylated analogue, where the hexaamine acts as a bridging ligand between the two square-pyramidal metal centres. Electronic and EPR spectroscopy are both consistent with these structures being maintained in solution.

References

1. W. Gauss, P. Moser and G. Schwarzenbach, Helv. Chim. Acta, 1952, 35, 2359.
2. F. Emmenegger, Ph.D. Thesis, ETH, Zürich, 1963.
3. K. Hata, M.-K. Doh, K. Kashiwabara and J. Fujita, Bull. Chem. Soc. Jpn., 1981, 54, 190.
4. C. O. Haagensen, Acta Chem. Scand., 1967, 21, 457.
5. A. Muto, F. Marumo and Y. Saito, Acta Crystallogr., Sect. B, 1970, 26, 226.
6. K. Sakai, Y. Tanaka and T. Tsubomura, Acta Crystallogr., Sect. C, 1996, 52, 541.
7. G. Schwarzenbach and P. Moser, Helv. Chim. Acta, 1953, 36, 581.
8. R. Alul, M. B. Cleaver and J.-S. Taylor, Inorg. Chem., 1992, 31, 3636.
9. B. D. Palmer, G. Wickham, D. J. Craik, W. D. McFadyen, L. P. G. Wakelin, B. C. Baguley and W. A. Denney, Anti-Cancer Drug Des., 1992, 7, 385.
10. G. P. Pez, I. L. Mador, J. A. Galle, R. K. Crissey and C. E. Forbes, J. Am. Chem. Soc., 1985, 107, 4098.
11. B. K. Wagnon and S. C. Jackels, Inorg. Chem., 1989, 28, 1923.
12. A. D. Zuberbühler and T. A. Kaden, Talanta, 1982, 29, 201.
13. R. A. Martinelli, G. R. Hanson, J. S. Thompson, B. Holmquist, J. R. Pilbrow, D. S. Auld and B. L. Vallee, Biochemistry, 1989, 28, 2251.
14. J. R. Pilbrow and T. D. Smith, Coord. Chem. Rev., 1974, 13, 173.
15. D. A. Cruse, J. E. Davies, M. Gerloch, J. H. Harding, D. J. Mackey and R. F. McMeeking, CAMMAG, a ligand-field computer program, University of Cambridge, 1991.
16. S. R. Hall, H. D. Flack and J. M. Stewart, (Editors), The XTAL 3.2 User's Manual, Universities of Western Australia, Geneva and Maryland, 1992.
17. G. M. Sheldrick, Acta Crystallogr., Sect. A, 1990, 46, 467.
18. G. M. Sheldrick, SHELXL 93, Program for Crystal Structure Determination, University of Göttingen, 1993.
19. A. L. Spek, Acta Crystallogr., Sect. A, 1990, 46, C34.
20. M. Duggan, N. Ray, B. Hathaway, G. Tomlinson, P. Brint and K. Pelin, J. Chem. Soc., Dalton Trans., 1980, 1342.
21. A. R. Rossi and R. Hoffmann, Inorg. Chem., 1975, 14, 365.
22. J. F. Boas, R. H. Dunhill, J. R. Pilbrow, R. C. Srivastava and T. D. Smith, J. Chem. Soc. A, 1969, 94.
23. N. D. Chasteen and R. L. Belford, Inorg. Chem., 1970, 9, 169.
24. L. G. Vanquickenborne and A. Ceulemans, Inorg. Chim. Acta, 1981, 20, 796.
25. M. J. Riley, Inorg. Chim. Acta, 1997, in the press.
26. N. Azuma, Y. Kohno, F. Nemoto, Y. Kajikawa, K. Ishizu, T. Takakuwa, S. Tsuboyama, K. Tsuboyama, K. Kobayashi and T. Sakurai, Inorg. Chim. Acta, 1994, 215, 109.
27. D. C. Olson and J. Vasilevskis, Inorg. Chem., 1971, 10, 463.
28. R. H. Wopschall and I. Shain, Anal. Chem., 1967, 39, 1514.
29. P. V. Bernhardt, J. Am. Chem. Soc., 1997, 119, 771.
30. P. V. Bernhardt, R. Bramley, L. M. Engelhardt, J. M. Harrowfield, D. C. R. Hockless, B. R. Korybut-Daszkiewicz, E. R. Krausz, T. Morgan, A. M. Sargeson, B. W. Skelton and A. H. White, Inorg. Chem., 1995, 34, 3589.
31. P. V. Bernhardt, L. A. Jones and P. C. Sharpe, J. Chem. Soc., Dalton Trans., 1997, 1169.