The European Physical Journal E

, Volume 18, Issue 2, pp 149–158 | Cite as

NMR relaxation study of molecular dynamics in columnar and smectic phases of a PAMAM liquid-crystalline co-dendrimer

  • A. Van-QuynhEmail author
  • D. Filip
  • C. Cruz
  • P. J. Sebasti ao
  • A. C. Ribeiro
  • J. -M. Rueff
  • M. Marcos
  • J. L. Serrano
Original Article


We present the first results obtained by proton (1H) nuclear magnetic relaxation studies of molecular dynamics in a supermolecular liquid-crystal dendrimer exhibiting columnar rectangular and smectic-A phases. The 1H spin-lattice relaxation time (T1) dispersions are interpreted using two relaxation mechanisms associated with collective motions and local molecular reorientations of the dendritic segments in the low- and high-frequency ranges, respectively. The T1 values show a drop around 2.3 MHz that is attributed to a contribution coming from cross-relaxation between 1H and nitrogen nuclear spins. In the high-frequency range the motions appear to be of similar nature in both mesophases and are ascribed to reorientations of dendritic segments (belonging to the core and/or to the mesogenic units) characterized by two correlation times. Notable differences in the dynamics between the columnar and layered phases are observed in the low-frequency range. Depending on the mesophase they are discussed in terms of elastic deformations of the columns and layer undulations. In this study we find that the dendritic core influences the dynamics of the mesogenic units both for local and collective motions. These results can be understood in terms of spatial constraints imposed by the dendritic architecture and by the supermolecular arrangement in the mesophases.


61.30.-v Liquid crystals 61.18.Fs Magnetic resonance techniques; Mössbauer spectroscopy 


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  1. 1.
    D.N. Reinhoudt, M. Crego-Calama, Science 295, 2403 (2002)CrossRefPubMedGoogle Scholar
  2. 2.
    D. Schwarze-Haller, F. Noack, M. Vilfan, G.P. Crawford, J. Chem. Phys. 105, 4823 (1996).CrossRefGoogle Scholar
  3. 3.
    G.R. Newkome, C.N. Moorefield, F. Vögtle, Dendrimers and Dendrons: Concepts, Syntheses, Applications (Wiley-VCH Verlag, Weinheim, 2001).Google Scholar
  4. 4.
    G. Althoff, D. Frezzato, M. Vilfan, O. Stauch, R. Schubert, I. Vilfan, G.J. Moro, G. Kothe, J. Phys. Chem. B 106, 5506Google Scholar
  5. 5.
    R. La Ferla, J. Chem. Phys. 106, 688 (1997).CrossRefGoogle Scholar
  6. 6.
    J. Barberá, M. Marcos, J.L. Serrano, Chem. Eur. J. 5, 1834 (1999).CrossRefGoogle Scholar
  7. 7.
    B. Donnio, J. Barberá, R. Giménez, D. Guillon, M. Marcos, J. L. Serrano, Macromolecules 35, 370 (2002).CrossRefGoogle Scholar
  8. 8.
    J.-M. Rueff, J. Barberá, B. Donnio, D. Guillon, M. Marcos, J.L. Serrano, Macromolecules 36, 8368 (2003).CrossRefGoogle Scholar
  9. 9.
    D.A. Tomalia, H. Baker, J. Dewald, M. Hall, G. Kallos, S. Martin, J. Roeck, P. Smith, Polym. J. 17, 117 (1985).Google Scholar
  10. 10.
    D.A. Tomalia, H. Baker, J. Dewald, M. Hall, G. Kallos, S. Martin, J. Roeck, P. Smith, Macromolecules 19, 2466 (1986).CrossRefGoogle Scholar
  11. 11.
    R.Y. Dong, Nuclear Magnetic Resonance of Liquid Crystals, 2nd edition (Springer Verlag, Berlin, 1997) and references therein.Google Scholar
  12. 12.
    F. Noack, NMR Basic Principles, Applications (Springer Verlag, Berlin, 1978).Google Scholar
  13. 13.
    F. Noack, K.H. Schweikert, The Molecular Dynamics of Liquid Crystals (Kluwer Academic Publishers, Netherlands, 1994).Google Scholar
  14. 14.
    a) R. Kimmich, Bull. Magn. Reson. 1, 195 (1980). b) R. Kimmich, F. Winter, Prog. Colloid Polym. Sci. 71, 66 (1985) and references therein.Google Scholar
  15. 15.
    M. Vilfan, N. Vrbrančič-Kopač, P. Ziherl, G.P. Crawford, Appl. Magn. Reson. 17, 329 (1999).Google Scholar
  16. 16.
    see, for e.g., S.H. Koenig, W.E. Schilinger, J. Biol. Chem. 244, 3283 (1969)PubMedGoogle Scholar
  17. 17.
    A.C. Ribeiro, P.J. Sebastião, C. Cruz, Mol. Cryst. Liq. Cryst. 362, 289 (2001).Google Scholar
  18. 18.
    A. Carvalho, P.J. Sebastião, A.C. Ribeiro, H.T. Nguyen, M. Vilfan, J. Chem. Phys. 115, 10484 (2001).Google Scholar
  19. 19.
    C. Cruz, J.L. Figueirihnas, P.J. Sebastião, A.C. Ribeiro, F. Noack, H.T. Nguyen, B. Heinrich, D. Guillon, Z. Naturforsch. 51a, 155 (1996).Google Scholar
  20. 20.
    U. Zeuner, T. Dippel, F. Noack, K. Müller, C. Mayer, N. Heaton, G. Kothe, J. Chem. Phys. 97, 3794 (1992).CrossRefGoogle Scholar
  21. 21.
    D. Filip, C. Cruz, P.J. Sebastião, A.C. Ribeiro, M. Vilfan, T. Meyer, G. Mehl, unpublishedGoogle Scholar
  22. 22.
    A. Skoulios, D. Guillon, Mol. Cryst. Liq. Cryst. 165, 317 (1988).Google Scholar
  23. 23.
    F. Noack, Prog. NMR Spectrosc. 18, 171 (1986)CrossRefGoogle Scholar
  24. 24.
    D.M. Sousa, G.D. Marques, P.J. Sebastião, A.C. Ribeiro, Rev. Sci. Instrum. 74, 4521 (2003)Google Scholar
  25. 25.
    A.D. Meltzer, D.A. Tirrell, A.A. Jones, P. Inglefield, D.M. Hedstrand, D.A. Tomalia, Macromolecules 25, 4541 (1992)Google Scholar
  26. 26.
    D.I. Malyarenko, R.L. Vold, G.L. Hoatson, Macromolecules 33, 1268 (2000).CrossRefGoogle Scholar
  27. 27.
    C. Cruz, P.J. Sebastião, J. Figueirinhas, A.C. Ribeiro, H.T. Nguen, C. Destrade, F. Noack, Z. Naturforsch. 53a, 823 (1998).Google Scholar
  28. 28.
    C.P. Slichter, Principles of Magnetic Resonance, 3rd enlarged and updated edition (Spinger Verlag, Berlin, 1990).Google Scholar
  29. 29.
    F. Winter, R. Kimmich, Mol. Phys. 45, 33 (1982).Google Scholar
  30. 30.
    D. Pusiol, F. Noack, Liq. Cryst. 5, 377 (1989)Google Scholar
  31. 31.
    P.J. Sebastião, A.C. Ribeiro, H.T. Nguyen, F. Noack, J. Phys. II 5, 1707 (1995).CrossRefGoogle Scholar
  32. 32.
    C.G. Wade, Annu. Rev. Phys. Chem. 28, 47 (1977).CrossRefGoogle Scholar
  33. 33.
    A. Abragam, The Principles of Nuclear Magnetism (Claredon Press, Oxford, 1961).Google Scholar
  34. 34.
    P. Ukleja, J. Pirs, J.W. Doane, Phys. Rev. A 14, 414 (1976).Google Scholar
  35. 35.
    R. Blinc, M. Luzar, M. Vilfan, M. Burgar, J. Chem. Phys. 63, 3445 (1975)Google Scholar
  36. 36.
    S. Žumer, M. Vilfan, Mol. Cryst. Liq. Cryst. 70, 39 (1981).Google Scholar
  37. 37.
    N. Bloembergen, E.M. Purcell, R.V. Pound, Phys. Rev. 73, 679 (1948).Google Scholar
  38. 38. Scholar
  39. 39.
    A.C. Ribeiro, P.J. Sebastião, C. Cruz, Pramana 61, 205 (2003).Google Scholar
  40. 40.
    K. Kihlhammer, K. Müller, G. Kothe, Liq. Cryst. 5, 1525 (1989)Google Scholar
  41. 41.
    P.J. Sebastião, A.C. Ribeiro, H.T. Nguyen, F. Noack, Z. Naturforsch. 48a, 851 (1993). Google Scholar
  42. 42.
    P.G. de Gennes, The Physics of Liquid Crystals (Clarendon Press, Oxford, 1974).Google Scholar
  43. 43.
    M. Kléman, P. Oswald, J. Phys. (Paris) 43, 655 (1982).Google Scholar

Copyright information

© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2005

Authors and Affiliations

  • A. Van-Quynh
    • 1
    Email author
  • D. Filip
    • 1
    • 4
  • C. Cruz
    • 1
    • 2
  • P. J. Sebasti ao
    • 1
    • 2
  • A. C. Ribeiro
    • 1
    • 2
  • J. -M. Rueff
    • 3
  • M. Marcos
    • 3
  • J. L. Serrano
    • 3
  1. 1.Centro de Fısica da Matéria CondensadaUniversidade de LisboaLisboaPortugal
  2. 2.IST-ULLisboaPortugal
  3. 3.Departamento de Quimica Orgánica, Nuevos Materiales OrgánicosUniversidad de Zaragoza-CSICZaragozaSpain
  4. 4.“Petru Poni” Institute of Macromolecular ChemistryIasiRomania

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