View PDF Version
 
DOI: 10.1039/A800821C (Paper) Reference Section for: J. Chem. Soc., Dalton Trans., 1998, 2053-2058

A ditopic tetradentate pyridyl amine ligand containing an anthracene fragment: fluorescence intensity and ‘closed’ vs. ‘open’ species formation in the presence of Cu2+, as a function of pH

(Note: The full text of this document is currently only available in the PDF Version )

Valeria Amendola, Luigi Fabbrizzi, Piersandro Pallavicini, Luisa Parodi and Angelo Perotti

Abstract

The compounds 9,10-bis(2-pyridylmethylaminoethyl)anthracene L1 and 9-(2-pyridylmethylaminomethyl)anthracene L2, based on nitrogen donors of the amine and pyridine type, were prepared and their properties examined in aqueous solution (water–1,4-dioxane 1∶4 v/v). The protonation constants of both have been determined by means of potentiometric titrations and the obtained species vs. pH distribution diagrams superimposed on the fluorescence intensity vs. pH profiles. This revealed an ‘off-on-off[hair space]’ window behaviour: the fluorescence intensity is high only in the pH range in which both free pyridine and protonated amines exist. Moreover, the formation constants of the complex species which form in the presence of 1 or 0.5 (in the case of L1 and L2, respectively) equivalent of CuII have been determined by means of potentiometric titrations. In particular, in the case of the tetradentate ditopic ligand L1 the ‘closed’ two ligand–two metal species [Cu2L12]4+ and [Cu2L12(OH)]3+ form in basic solution, in addition to two ligand–one metal partially protonated ‘open’ complex species. Moreover, a strong variation of the fluorescence intensity of the anthracene fragment signals the formation of the ‘closed’ species with respect to the ‘open’ ones, while a more subtle variation of the fluorescence intensity also allows one to distinguish between [Cu2L12]4+ and [Cu2L12(OH)]3+.

References

  1. J.-M. Lehn, in Supramolecular Chemistry, VCH, Weinheim, 1995, pp. 146–154 Search PubMed.
  2. C. O. Dietrich-Buchecker, J. Guilham, A. K. Khemiss, J. P. Kintzinger, C. Pascard and J. P. Sauvage, Angew. Chem., Int. Ed. Engl., 1987, 28, 661 CrossRef.
  3. B. Linton and A. D. Hamilton, Chem. Rev., 1997, 97, 1669 CrossRef CAS; A. W. Maverick, S. C. Buckingham, Q. Yao, J. R. Bradbury and G. G. Stanley, J. Am. Chem. Soc., 1986, 108, 7430 CrossRef CAS; M. Fujita, S. Nagao and K. Ogura, J. Am. Chem. Soc., 1995, 117, 1649 CrossRef CAS; R. W. Saalfrank, B. Horner, D. Stalke and J. Salbeck, Angew. Chem., Int. Ed. Engl., 1993, 32, 1179 CrossRef.
  4. M. Fujita, J. Yazaki and K. Ogura, J. Am. Chem. Soc., 1990, 112, 5645 CrossRef CAS; C. M. Drain and J.-M. Lehn, J. Chem. Soc., Chem. Commun., 1994, 2113 RSC; C. A. Hunter and L. D. Sarson, Angew. Chem., Int. Ed. Engl., 1994, 33, 2313 CrossRef.
  5. J.-C. Chambron, C. O. Dietrich-Buchecker, J.-F. Nierengarten and J.-P. Sauvage, J. Chem. Soc., Chem. Commun., 1993, 801 RSC.
  6. G. S. Hanan, C. R. Arana, J.-M. Lehn, G. Baum and D. Fenske, Chem. Eur. J., 1996, 2, 1292 CrossRef CAS; G. S. Hanan, C. R. Arana, J.-M. Lehn and D. Fenske, Angew. Chem., Int. Ed. Engl., 1995, 34, 1122 CrossRef CAS.
  7. G. S. Hanan, D. Volkmer, U. S. Schubert, J.-M. Lehn, G. Baum and D. Fenske, Angew. Chem., Int. Ed. Engl., 1997, 36, 1842 CrossRef.
  8. A. P. de Silva, H. Q. N. Gunaratne and C. P. McCoy, Chem. Commun., 1996, 2399 RSC.
  9. A. P. de Silva, H. Q. N. Gunaratne, T. Gunnlaugsson, A. J. M. Huxley, C. P. McCoy, J. T. Rademacher and T. E. Rice, Chem. Rev., 1997, 97, 1515 CrossRef; L. Fabbrizzi, G. Francese, M. Licchelli, P. Pallavicini, A. Perotti, A. Poggi, D. Sacchi and A. Taglietti, in Chemosensors of Ion and Molecule Recognition, NATO ASI series, eds. J. P. Desvergne and A. W. Czarnik, Kluwer, Dordrecht, 1997 Search PubMed; L. Fabbrizzi, M. Licchelli, P. Pallavicini, D. Sacchi and A. Taglietti, Analyst (London), 1996, 121, 1763 Search PubMed; L. Fabbrizzi, M. Licchelli, P. Pallavicini, A. Perotti, A. Taglietti and D. Sacchi, Chem. Eur. J., 1996, 2, 75 RSC.
  10. E. U. Akkaya, M. E. Huston and A. W. Czarnik, J. Am. Chem. Soc., 1990, 112, 1967; L. Fabbrizzi, M. Licchelli, P. Pallavicini and A. Taglietti, Inorg. Chem., 1996, 35, 1733 CrossRef CAS.
  11. A. Sabatini, A. Vacca and P. Gans, Coord. Chem. Rev., 1992, 120, 389 CrossRef CAS.
  12. (a) G. De Santis, L. Fabbrizzi, D. Iacopino, P. Pallavicini, A. Perotti and A. Poggi, Inorg. Chem., 1997, 36, 827 CrossRef and refs. therein; (b) L. Fabbrizzi, P. Pallavicini, L. Parodi and A. Taglietti, J. Chem. Soc., Chem. Commun., 1995, 2439 RSC.
  13. A. Bencini, A. Bianchi, P. Paoletti and E. Garcia-España, in Transition Metals in Supramolecular Chemistry, NATO ASI series, eds. L. Fabbrizzi and A. Poggi, Kluwer, Dordrecht, 1994 Search PubMed; R. J. Motekaitis, A. E. Martell, J.-M. Lehn and E. Watanabe, Inorg. Chem., 1982, 21, 4253 Search PubMed.
  14. M. W. Miller, R. W. Amidon and P. O. Tawney, J. Am. Chem. Soc., 1955, 77, 2845 CrossRef CAS.
  15. G. Gran, Analyst (London), 1952, 77, 661 RSC.
  16. A. Sabatini and A. Vacca, J. Chem. Soc., Dalton Trans., 1972, 1693 RSC; A. Sabatini, A. Vacca and P. Gans, Talanta, 1974, 21, 53 CrossRef CAS; P. Gans, A. Sabatini and A. Vacca, Inorg. Chim. Acta, 1976, 18, 239 CrossRef; J. Chem. Soc., Dalton Trans., 1985, 1195 Search PubMed.
  17. E. Wolley, J. Phys. Chem., 1970, 74, 3908 CrossRef.
  18. P. Gans, Data Fitting in the Chemical Sciences, Wiley, Chichester, 1992 Search PubMed.
Click here to see how this site uses Cookies. View our privacy policy here.