Nitrogen- and carbon-based isomerism in the copper(II) complexes of 6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane-6,13-diamine

Abstract

A number of N- and C-based diastereomeric copper(II) complexes of the pendant-arm macrocyclic hexaamines trans- and cis- 6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane-6,13-diamine (L¹ and L²) have been isolated and characterised. The crystal structures of the complexes RRSS-[CuL¹(OH₂)₂][ClO₄ ]₂, SSRR-[Cu(H₂L¹)(OClO₃)₂ ][ClO₄]₂·2H₂O, RSRS-[CuL¹(OClO₃)]ClO₄, RSRS-[CuL²(OClO₃)]ClO₄ and RRSS-[Cu(H₂L²)(OClO₃)₂ ][ClO₄]₂ have been determined. Some unusual structural and spectroscopic variations are found across this series of diastereomers. The protonation constants of the pendant primary amines are dependent on the relative dispositions of the adjacent macrocyclic secondary amine H atoms, which is indicative of intramolecular hydrogen-bonding interactions.

References

1. P. V. Bernhardt, P. Comba, T. W. Hambley and G. A. Lawrance, Inorg. Chem., 1991, 30, 942.
2. P. V. Bernhardt, P. Comba and T. W. Hambley, Inorg. Chem., 1993, 32, 2804.
3. P. G. Lye, G. A. Lawrance, M. Maeder, B. W. Skelton, H. Wen and A. H. White, J. Chem. Soc., Dalton Trans., 1994, 793.
4. B. Bosnich, C. K. Poon and M. Tobe, Inorg. Chem., 1965, 4, 1102.
5. N. F. Curtis, G. J. Gainsford, A. Siriwardena and D. C. Weatherburn, Aust. J. Chem., 1993, 46, 755.
6. G. A. Lawrance, B. W. Skelton, A. H. White and P. Comba, Aust. J. Chem., 1986, 39, 1101.
7. P. Comba, N. F. Curtis, G. A. Lawrance, A. M. Sargeson, B. W. Skelton and A. H. White, Inorg. Chem., 1986, 25, 4260.
8. P. V. Bernhardt, P. Comba, T. W. Hambley, G. A. Lawrance and K. Várnagy, J. Chem. Soc., Dalton Trans., 1992, 355.
9. A. D. Zuberbühler and T. A. Kaden, Talanta, 1982, 29, 201.
10. S. R. Hall, H. D. Flack and J. M. Stewart(Editors), The XTAL3.2 User's Manual, Universities of Western Australia, Geneva and Maryland, 1992.
11. N. Walker and D. Stuart, Acta Crystallogr., Sect. A, 1983, 39, 158.
12. G. M. Sheldrick, Acta Crystallogr., Sect. A, 1990, 46, 467.
13. G. M. Sheldrick, SHELXL 93, Program for Crystal Structure Determination, University of Göttingen, 1993.
14. A. L. Spek, Acta Crystallogr., Sect. A, 1990, 46, C34.
15. A. L. Spek, PLUTON 92, University of Utrecht, 1992.
16. J. Gažo, I. B. Bersuker, J. Garaj, M. Kabešová, J. Kohout, H. Lagfelderová, M. Melník, M. Serátor and F. Valach, Coord. Chem. Rev., 1976, 19, 253.
17. P. V. Bernhardt, J. Chem. Soc., Dalton Trans., 1996, 4319.
18. J. D. Dunitz and J. Bernstein, Acc. Chem. Res., 1995, 28, 193.
19. P. V. Bernhardt, G. A. Lawrance, P. Comba, L. L. Martin and T. W. Hambley, J. Chem. Soc., Dalton Trans., 1990, 2859.
20. N. F. Curtis, W. T. Robinson and D. C. Weatherburn, Aust. J. Chem., 1992, 45, 1663.
21. N. F. Curtis, D. A. Swann and T. N. Waters, J. Chem. Soc., Dalton Trans., 1973, 1963.
22. R. Bembi, M. G. B. Drew, R. Singh and T. G. Hay, Inorg. Chem., 1991, 30, 1403.
23. P. V. Bernhardt, J. M. Harrowfield, D. C. R. Hockless and A. M. Sargeson, Inorg. Chem., 1994, 33, 5659 and refs. therein.
24. M. J. D'aniello, jun., M. T. Mocella, F. Wagner, E. K. Barefield and I. C. Paul, J. Am. Chem. Soc., 1975, 97, 192.
25. P. V. Bernhardt, G. A. Lawrance, M. Maeder, M. Rossignoli and T. W. Hambley, J. Chem. Soc., Dalton Trans., 1991, 1167.
26. P. Comba, T. W. Hambley, M. A. Hitchman and H. Stratemeier, Inorg. Chem., 1995, 34, 3903.
27. P. V. Bernhardt and P. C. Sharpe, Chem. Commun., 1996, 1267.
28. L. H. Chen and C. S. Chung, Inorg. Chem., 1988, 27, 1880.
29. D. K. Cabbiness and D. W. Margerum, J. Am. Chem. Soc., 1970, 92, 2151.
30. M. Kodama and E. Kimura, J. Chem. Soc., Dalton Trans., 1976, 2341.
31. E. Gallori, E. Martini, M. Micheloni and P. Paoletti, J. Chem. Soc., Dalton Trans., 1980, 1722.
32. 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.