Thermodynamic and fluorescence emission studies on chemosensors containing anthracene fluorophores. Crystal structure of {[CuL¹Cl]Cl}₂·2H₂O [L¹ = N-(3-aminopropyl)-N ′-3-(anthracen-9-ylmethyl)aminopropylethane-1,2-diamine]

Abstract

The co-ordination capabilities toward hydrogen ions, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ and Cd²⁺ of the novel receptor 2,6,9,13-tetraaza[14](9,10)anthracenophane (L) and of its open-chain counterpart N-(3-aminopropyl)-N ′-3-(anthracen-9-ylmethyl)aminopropylethane-1,2-diamine (L¹) is described. Stepwise protonation constants of the cyclic receptor (L) are lower than those of the open-chain receptor (L¹) . Quenching effects of the fluorescence emission occur upon first and second deprotonation of L and upon second deprotonation of L¹. Stability constants of the Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ and Cd²⁺ complexes follow the Irving–Williams trend and are intermediate between those of triethylenetetraamine with terminal primary amino groups and those of the α,ω-dibenzylated receptor 1,12-dibenzyl-1,5,8,12-tetraazaciclododecane. Luminescence studies show that complexation of Cu²⁺ and Ni²⁺ by L¹ yield CHEQ effects (chelation enhanced quenching) while complexation of Zn²⁺ and Cd²⁺ produce CHEF effects (chelation enhanced fluorescence). The magnitude of these effects depends on the strength of the co-ordination. Crystals of {[CuL¹Cl]Cl}₂· 2H₂O are triclinic, space group P1̄, with a = 13.307(1), b = 13.305(1), c = 16.538(2) Å, α = 104.94(1), β = 111.67(1), γ = 102.76(1)°, R₁ = 0.0885, wR₂ = 0.2667. The crystal structure of {[CuL¹Cl]Cl}₂·2H₂O shows a very strongly axially distorted square pyramidal co-ordination geometry in which the Cu²⁺ cation is co-ordinated by all the nitrogen donors of the receptor and a chloride ion disposed at the apical position of the square pyramid. The asymmetric unit is formed by two slightly different [CuL¹Cl]⁺ cations with an arrangement that shows π-stacking of their anthracene sub-units.

References

1. J. M. Lehn, Supramolecular Chemistry, Concepts and Perspectives, VCH, Weinheim, 1996.
2. V. Balzani and F. Scandola, Supramolecular Photochemistry, Ellis Horwood, Chichester, 1991.
3. Fluorescent Chemosensors for Ion and Molecule Recognition, ed. W. Czarnik, ACS, Symposium Series 538, American Chemical Society, Washington DC, 1992; Chemosensors for Ion and Molecule Recognition, eds. J. P. Desvergne and A. W. Czarnik, Kluwer, Dordrecht, 1997.
4. M. E. Huston, E. U. Akkaya and A. W. Czarnik, J. Am. Chem. Soc., 1989, 111, 8735; E. U. Akkaya, M. E. Huston and A. W. Czarnik, J. Am. Chem. Soc., 1990, 112, 3590; S. A. Van Arman and A. W. Czarnik, J. Am. Chem. Soc., 1990, 112, 5376.
5. L. Fabbrizzi, M. Licchelli, P. Pallavicini, A. Perotti, A. Taglietti and D. Sacchi, Chem. Eur. J., 1996, 1, 75; L. Fabbrizzi, M. Licchelli, P. Pallavicini and A. Taglietti, Inorg. Chem., 1996, 35, 1733; L. Fabbrizzi, M. Licchelli, P. Pallavicini and L. Parodi, Angew. Chem., Int. Ed. Engl., 1996, 35, 1733.
6. R. A. P. de Silva and S. A. de Silva, J. Chem. Soc., Chem. Commun., 1986, 1709; R. A. Bissell, A. P. de Silva, H. Q. N. Gunaratne, P. L. M. Lynch, G. E. M. Maguire and K. R. A. S. Sandanayake, Chem. Soc. Rev., 1992, 21, 18; R. A. Bissell, A. P. de Silva, H. Q. N. Gunaratne, P. L. M. Lynch, C. P. McCoy, G. E. M. Maguire and K. R. A. S. Sandanayake, Top. Curr. Chem., 1998, 37, 800; A. P. de Silva, H. Q. N. Gunaratne, T. Gunnlaugsson, C. P. McCoy, J. T. Rademacher and T. E. Rice, Chem. Rev., 1997, 97, 1515.
7. L. R. Sousa and J. M. Larson, J. Am. Chem. Soc., 1977, 99, 307; J. M. Larson and L. R. Sousa, J. Am. Chem. Soc., 1978, 100, 1943.
8. H. Shizuka, K. Takada and T. Morita, J. Phys. Chem., 1980, 84, 994.
9. H. Bouas-Laurent, A. Castellan, M. Daney, J.-P. Desvergne, G. Guinand, P. Marsau and M.-H. Riffaud, J. Am. Chem. Soc., 1986, 108, 315.
10. B. Valeur, J. Bourson, J. Pouget, M. Kaschke and N. P. Nernsting, J. Phys. Chem., 1992, 96, 6545.
11. M. A. Bernardo, A. J. Parola, F. Pina, E. Garcia-España, V. Marcelino, S. V. Luis and J. F. Miravet, J. Chem. Soc., Dalton Trans., 1995, 993.
12. (a) M. A. Bernardo, J. A. Guerrero, E. García-España, S. V. Luis, J. M. Llinares, F. Pina, J. A. Ramirez and C. Soriano, J. Chem. Soc., Perkin Trans. 2, 1996, 2335; (b) M. A. Bernardo, F. Pina, E. García-España, J. Latorre, S. V. Luis, J. M. Llinares, J. A. Ramirez and C. Soriano, Inorg. Chem., 1998, 37, 3935.
13. M. I. Burguete, B. Escuder, S. V. Luis, J. F. Miravet, M. Querol and E. García-España, Tetrahedron Lett., 1998, 39, 3799.
14. M. Micheloni, A. Sabatini and A. Vacca, Inorg. Chim. Acta, 1977, 25, 41.
15. E. García-España, M.-J. Ballester, F. Lloret, J.-M. Moratal, J. Faus and A. Bianchi, J. Chem. Soc., Dalton Trans., 1988, 101.
16. M. Fontanelli and M. Micheloni, Proceedings of the I Spanish–Italian Congress on Thermodynamics of Metal Complexes, Diputación de Castellón, Castellón, Spain, 1990.
17. G. Gran, Analyst (London), 1952, 77, 881; F. J. Rossotti and H. Rossotti, J. Chem. Educ., 1965, 42, 375.
18. A. Sabatini, A. Vacca, A. Gans and P. Gans, Coord. Chem. Rev., 1992, 120, 389.
19. C. Mealli and D. Proserpio, J. Chem. Educ., 1990, 67, 399.
20. M. S. Lehman and F. K. Larsen, Acta Crystallogr., Sect. A, 1978, 30, 580; D. F. Grant and E. J. Gabe, J. Appl. Crystallogr., Sect. A, 1978, 11, 114.
21. A. C. T. North, D. C. Philips and F. S. Mathews, Acta Crystallogr., Sect. A, 1968, 24, 351.
22. Crystallographic Computing, eds. G. M. Sheldrick, C. Kruger and R. Goddard, Clarendon Press, Oxford, 1985, p. 175.
23. G. M. Sheldrick, SHELXS-93: Program for Crystal Structure Refinement, Institute für Anorganische Chemie de Universitat, Göttingen, 1993.
24. International Tables for X-Ray Crystallography, Kynoch Press, Birmingham, 1974, vol. IV.
25. C. K. Johnson, ORTEP, Report ORNL-3794, Oak Ridge National Laboratory, Oak Ridge, TN, 1971.
26. A. Andrés, M. I. Burguete, E. García-España, S. V. Luis, J. F. Miravet and C. Soriano, J. Chem. Soc., Perkin Trans. 2, 1993, 749; A. Bianchi, B. Escuder, E. García-España, S. V. Luis, V. Marcelino, J. F. Miravet and J. A. Ramírez, J. Chem. Soc., Perkin Trans. 2, 1994, 1253.
27. E. Martell, R. M. Smith and R. J. Motekaitis, NIST Critically Selected Stability Constants of Metal Complexes Database, NIST Standard Reference Database, version 4, 1997.
28. J. E. Sarnesky, H. L. Surprenant, F. K. Molen and E. N. Reiley, Anal. Chem., 1975, 47, 2116; A. Bencini, A. Bianchi, E. García-España, M. Micheloni and J. A. Ramírez, Coord. Chem. Rev., 1999, in press.
29. A. Andrés, C. Bazzicalupi, A. Bianchi, E. García-España, S. V. Luis, J. F. Miravet and J. A. Ramírez, J. Chem. Soc., Dalton Trans., 1994, 2995.
30. B. Altava, M. I. Burguete, S. V. Luis, J. F. Miravet, E. García-España, V. Marcelino and C. Soriano, Tetrahedron, 1997, 53, 4751; M. I. Burguete, B. Escuder, J. C. Frías, E. García-España, S. V. Luis and J. F. Miravet, Tetrahedron, 1998, 63, 1810.
31. E. García-España, J. Latorre, S. V. Luis, J. F. Miarvet, P. Pozuelo, J. A. Ramírez and C. Soriano, Inorg. Chem., 1996, 35, 4591.