Co-ordination ability of novel tetradentate amide-and-oxime ligands: differential binding to Cu^II and Ni^II

Abstract

Four cationic and anionic complexes of Ni^II and Cu^II with new open chain oxime-and-amide ligands, N,N ′-bis(2-hydroxyiminopropionyl)-1,2-diaminoethane (H₂pen) and 1,4-diaminobutane (H₂pab) were isolated and characterised by X-ray crystallography and a variety of spectroscopic techniques. The ligands were found to exhibit two types of co-ordination modes depending on pH: N(oxime),O(amide) bis-bidentate and N₂(oxime),N₂(amide) tetradentate. The first bonding mode leads to bridging of the two ligands thus forming binuclear cationic complexes [{Cu(Hpab)(ClO₄)·2H₂O}₂] 1b and Li[Ni(H_–1pen)]·4H₂O 2a which have been determined by single-crystal X-ray analysis. In 1b the bis-bidentate co-ordination mode leads to the formation of a dimeric complex cation containing a loose 22-membered macrocyclic cavity incorporating two Cu^II ions as a part of the ring skeleton. The central atoms in 1b are distorted square-pyramidal with the water molecule in the apical position. N₄-tetradentate co-ordination observed in 2a leads to the formation of a square-planar complex anion with a closed pseudo-macrocyclic environment stabilised by a short intramolecular H-bond between the oxime oxygen atoms.

References

1. A. M. Duda, A. Karaczyn, H. Kozłowski, I. O. Fritsky, T. Głowiak, E. V. Prisyazhnaya, T. Yu. Sliva and J. Świątek-Kozłowska, J. Chem. Soc., Dalton Trans., 1997, 3853.
2. E. V. Rybak-Akimova, D. H. Busch, P. K. Kahol, N. Pinto, N. W. Alcock and H. J. Clase, Inorg. Chem., 1997, 36, 510; E. Colacia, J. M. Domingues-Vera, A. Escuer, R. Kivekäs, M. Klinga, J.-M. Moreno and A. Romerosa, J. Chem. Soc., Dalton Trans., 1997, 1685; D. Burdinski, F. Birkelbach, M. Gerdan, A. X. Trautwein, K. Wieghardt and P. Chaudhuri, J. Chem. Soc., Chem. Commun., 1995, 963.
3. F. Birkelbach, T. Weyhermüller, M. Lengen, M. Gerdan, A. X. Trautwein, K. Wieghardt and P. Chaudhuri, J. Chem. Soc., Dalton Trans., 1997, 4529.
4. T. Yu. Sliva, T. Kowalik-Jankowska, V. M. Amirkhanov, T. Głowiak, C. O. Onindo, I. O. Fritsky and H. Kozłowski, J. Inorg. Biochem., 1997, 65, 287.
5. T. Yu. Sliva, A. M. Duda, T. Głowiak, I. O. Fritsky, V. M. Amirkhanov, A. A. Mokhir and H. Kozłowski, J. Chem. Soc., Dalton Trans., 1997, 273.
6. A. Earnshaw, Introduction to Magnetochemistry, Academic Press, London, New York, 1968.
7. I. O. Fritsky, A. Karaczyn, H. Kozłowski, T. Głowiak and E. V. Prisyazhnaya, Pol. J. Chem., submitted.
8. E. V. Prisyazhnaya, I. O. Fritsky, V. V. Skopenko and V. A. Kalibabchuk, unpublished work.
9. G. M. Sheldrick, Acta Crystallogr., Sect. A., 1990, 46, 467.
10. G. M. Sheldrick, SHELXL 93, University of Göttingen, 1993.
11. International Tables for Crystallography, Kynoch Press, Birmingham, 1974, vol. 4.
12. M. E. Keeney, K. Osseo-Asare and K. A. Wood, Coord. Chem. Rev., 1984, 59, 141; V. V. Skopenko, I. O. Fritskii, R. D. Lampeka and T. S. Iskenderov, Russ. J. Inorg. Chem. (Engl. Transl.), 1993, 38, 1708.
13. C. O. Onindo, T. Yu. Sliva, T. Kowalik-Jankowska, I. O. Fritsky, P. Buglyo, L. D. Pettit, H. Kozłowski and T. Kiss, J. Chem. Soc., Dalton Trans., 1995, 3911.
14. R. D. Lampeka, I. O. Fritsky and T. Yu. Sliva, unpublished work.
15. J. C. Ching and E. O. Schlemper, Inorg. Chem., 1975, 14, 2470; J. Pal, R. K. Murmann, E. O. Schlemper, C. K. Fair and M. S. Hussain, Inorg. Chim. Acta, 1986, 115, 153.
16. S. M. Polson, R. Cini, C. Pifferi and L. G. Marzilli, Inorg. Chem., 1997, 36, 214.
17. I. O. Fritsky, R. D. Lampeka, V. Kh. Kravtsov and Yu. A. Simonov, Acta Crystallogr., Sect. C, 1993, 49, 1041; V. Kh. Kravtsov, Yu. A. Simonov, V. V. Skopenko, I. O. Fritskii, R. D. Lampeka and T. I. Malinowsky, Zh. Neorg. Khim., 1993, 38, 1981.
18. I. O. Fritskii, R. D. Lampeka, V. V. Skopenko, Yu. A. Simonov and A. A. Dvorkin, Russ. J. Inorg. Chem. (Engl. Transl.), 1994, 39, 771.
19. Yu. A. Simonov, V. Kh. Kravtsov, I. O. Fritskii, E. E. Gubina, R. D. Lampeka, T. S. Iskenderov and A. Zh. Zhumabaev, Koord. Khim., 1995, 21, 407.
20. B. Bleaney and K. D. Bowers, Proc. R. Soc. London, Ser. A, 1952, 214, 451.
21. M. S. Hussain and E. O. Schlemper, Inorg. Chem., 1979, 18, 2275.