View PDF Version
 
DOI: 10.1039/A703347H (Paper) Reference Section for: J. Chem. Soc., Perkin Trans. 2, 1997, 2249-2256

Structure and ion-complexing properties of an aza-15-crown-5 ether dye: synthesis, crystallography, NMR spectroscopy, spectrophotometry and potentiometry

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

M. V. Alfimov, A. V. Churakov, Y. V. Fedorov, O. A. Fedorova, S. P. Gromov, R. E. Hester, J. A. K. Howard, L. G. Kuz’mina, I. K. Lednev and J. N. Moore

Abstract

The perchlorate of 2-{2-[4-(13-aza-1,4,7,10-tetroxa-13-cyclopentadecyl)phenyl]ethenyl}-3-ethylbenzothiazolium (3) has been synthesised and its structure determined in the crystalline state by X-ray diffraction and in solution in acetonitrile by 1H NMR methods. Complexation with barium and silver cations in solution has been studied in comparison with other model azacrown molecules by spectrophotometric and potentiometric methods. With the exception of the puckered azacrown moiety, the structure of 3 is remarkably planar, consistent with extensive π-conjugation throughout the remainder of the molecule in both solid and solution states. Compound 3 forms a stable 1∶1 complex with Ba2+ ions in acetonitrile, with a stability constant of K1 = 80 ± 10 dm3 mol–1; the complexation results in major changes in the electronic absorption spectrum of 3, consistent with binding to the azacrown moiety. A model compound, phenylaza-15-crown-5 (2a), was found to bind Ba2+ to form both a 1∶1 ligand–metal complex (LM), with a stability constant of K1 = (2.0 ± 0.2) × 104 dm3 mol–1, and a 2∶1 (L2M) complex, with a stability constant of K2 = 220 ± 20 dm3 mol–1 for binding of the second ligand. The electronic absorption and NMR spectra both indicate binding of the ‘hard’ Ba2+ cation to the azacrown oxygen atoms. However, by contrast, the evidence from NMR data shows that the ‘soft’ Ag+ cation complexes with 2a mainly through a strong interaction with the azacrown nitrogen atom, giving a 1∶1 complex with a stability constant of K1 = 6 ± 1 dm3 mol–1, determined by potentiometry. No complexation of 3 with Ag+ is observed. Studies of the simple aza-15-crown-5 ether reveal strong complexation with both Ba2+ (K1 × K2 > 1012 dm6 mol–2) and Ag+ [K1 = (1.15 ± 0.10) × 104 dm3 mol–1 and K2 = 450 ± 20 dm3 mol–1].

References

  1. J.-M. Lehn, Supramolecular Chemistry. Concepts and Perspectives, VCH, Weinheim, 1995 Search PubMed.
  2. S. R. Cooper, ed., Crown Compounds: Toward Future Applications, VCH, New York, 1992.
  3. B. Valeur and E. Bardez, Chem. Br., 1995, 31, 216 Search PubMed.
  4. L. Fabbrizzi and A. Poggi, Chem. Soc. Rev., 1995, 197 RSC.
  5. J. D. Wright, Chem. Br., 1995, 31, 374 Search PubMed.
  6. A. P. de Silva and C. P. McCoy, Chem. Ind. (London), 1994, 992 CAS.
  7. M. Takagi, in Cation Binding by Macrocycles, ed. Y. Inoue and G. W. Gokel, Marcel Dekker, New York, 1990, ch. 11, p. 465 Search PubMed.
  8. J. P. Dix and F. Vogtle, Chem. Ber., 1980, 113, 457 CrossRef CAS.
  9. J. Bourson, J. Pouget and B. Valeur, J. Phys. Chem., 1993, 97, 4552 CrossRef CAS.
  10. J. Bourson and B. Valeur, J. Phys. Chem., 1989, 93, 3871 CrossRef CAS.
  11. J. F. Letard, R. Lapouyade and W. Rettig, Pure Appl. Chem., 1993, 65, 1705 CrossRef CAS.
  12. M. V. Alfimov, S. P. Gromov and I. K. Lednev, Chem. Phys. Lett., 1991, 185, 455 CrossRef CAS.
  13. S. P. Gromov, O. A. Fedorova, E. N. Ushakov, O. B. Stanislavsky, I. K. Lednev and M. V. Alfimov, Dokl. Akad. Nauk SSSR, 1991, 317, 1134 Search PubMed.
  14. V. V. Tkachev, L. O. Atovmyan, S. P. Gromov, O. A. Fedorova and M. V. Alfimov, Zh. Strukt. Khim., 1992, 33, 126 Search PubMed.
  15. I. K. Lednev, S. P. Gromov, E. N. Ushakov, M. V. Alfimov, J. N. Moore and R. E. Hester, Spectrochim. Acta, Part A, 1992, 48, 799 CrossRef.
  16. I. K. Lednev, M. V. Fomina, S. P. Gromov, O. B. Stanislavsky, M. M. Alfimov, J. N. Moore and R. E. Hester, Spectrochim. Acta, Part A, 1992, 48, 931 CrossRef.
  17. I. K. Lednev, O. A. Fedorova, S. P. Gromov, M. V. Alfimov, J. N. Moore and R. E. Hester, Spectrochim. Acta, Part A, 1993, 49, 1055 CrossRef.
  18. M. V. Alfimov, Y. V. Fedorov, O. A. Fedorova, S. P. Gromov, R. E. Hester, I. K. Lednev, J. N. Moore, V. P. Oleshko and A. I. Vedernikov, J. Chem. Soc., Perkin Trans. 2, 1996, 1441 RSC.
  19. M. V. Alfimov, Y. V. Fedorov, O. A. Fedorova, S. P. Gromov, R. E. Hester, I. K. Lednev, J. N. Moore, V. P. Oleshko and A. I. Vedernikov, Spectrochim. Acta, 1997, in the press Search PubMed.
  20. O. A. Fedorova, S. P. Gromov and M. V. Alfimov, Dokl. Akad. Nauk. Khim., 1995, 341, 219 Search PubMed.
  21. M. C. Etter, R. B. Kress, J. Bernstein and D. J. Cash, J. Am. Chem. Soc., 1984, 106, 6921 CrossRef CAS.
  22. F. H. Allen, O. Kennard, D. G. Watson, L. Brammer, G. Orpen and R. Taylor, J. Chem. Soc., Perkin Trans. 2, 1987, S1 RSC.
  23. D. Zobel and G. Ruban, Acta Crystallogr., Sect. B, 1981, 37, 1867 CrossRef.
  24. R. Allman, H.-J. Anis, R. Benn, W. Grahn, S. Olejnek and A. Waskowska, Angew. Chem., Int. Ed. Engl., 1983, 22, 876 CrossRef.
  25. J. Stroka, T. Ossowski, B. G. Cox, A. Thaler and H. Schneider, Inorg. Chim. Acta, 1994, 219, 31 CrossRef CAS.
  26. H. K. Frensdorff, J. Am. Chem. Soc., 1971, 93, 600 CrossRef CAS.
  27. D. A. Gustowski, V. J. Gatto, J. Mallen, L. Echegoyen and G. W. Gokel, J. Org. Chem., 1987, 52, 5172 CrossRef CAS.
  28. B. Brzezinski, G. Schroeder, A. Rabold and G. Zundel, J. Phys. Chem., 1995, 99, 8519 CrossRef CAS.
  29. SAINT, Version 4.050, Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA, 1995.
  30. G. M. Sheldrick, SHELXLTL-Plus, Release 4.1, Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA, 1991.
  31. G. M. Sheldrick, Acta Crystallogr., Sect. A, 1990, 46, 467 CrossRef.
  32. G. M. Sheldrick, SHELXL-93 Program for the refinement of crystal structures, University of Göttingen, Germany, 1993.
Click here to see how this site uses Cookies. View our privacy policy here.