Dielectric and X-ray Studies of Eleventh and Twelfth Members of Two Isothiocyanato Mesogenic Compounds

• Authors: M. Jasiurkowska , A. Budziak , J. Czub , S. Urban
• Languages of publication: EN

Abstracts

EN

Results of the dielectric and X-ray studies of the long-alkyl-chain members (n=11, 12) of two homologous series: nBT (4-n-alkyl-4'-isothiocyanato-biphenyl) and nCHBT (4-trans-4'-n-alkyl-cyclohexyl-isothiocyanato-benzene) in their liquid crystalline phases are presented. These compounds exhibit different polymorphisms: the nematic phase for $n$CHBTs and the smectic E and smectic A phases for nBTs. The dielectric measurements were performed in a wide frequency range of 1 kHz-3 GHz. The layer thickness in the smectic E and smectic A phases and the orthorhombic unit cell parameters of the smectic E phase were determined using the small angle X-ray diffraction method. In the smectic E phase the layer-thickness-to-molecular-length ratios are found to be close to 1. The corresponding ratios observed for the smectic A phase of $n$BTs are considerably higher (≈1.24), which indicates that an alternating head-to-tail arrangement of molecules in the layers is favored. The rotational dynamics of molecules in the smectic E phases is discussed in relation to their packing in a unit cell.

Keywords

EN

61.10.Eq; 61.66.Hq; 64.70.Md; 77.22.-d; 77.22.Gm

Discipline

• 77.22.Gm: Dielectric loss and relaxation
• 77.22.-d: Dielectric properties of solids and liquids(for dielectric properties of tissues and organs, see 87.19.rf)
• 61.66.Hq: Organic compounds

• Journal: Acta Physica Polonica A
• Year: 2006
• Volume: 110
• Issue: 6
• Pages: 795-805

Dates

published

2006-12

received

2006-09-11

(unknown)

2006-11-27

Contributors

author

M. Jasiurkowska

• H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland

author

A. Budziak

• H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland

author

J. Czub

• Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland

author

S. Urban

• Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland

References

• 1. S. Urban, J. Czub, R. Dabrowski, A. Wurflinger, Phase Trans., 79, 331, 2006
• 2. P. Sarkar, P. Mandal, S. Paul, R. Paul, R. Dabrowski, K. Czupryński, Liq. Cryst., 30, 507, 2003
• 3. B. Gestblom, in: Relaxation Phenomena, Eds. W. Haase, S. Wróbel, Springer-Verlag, Berlin 2003, Ch. 1.2
• 4. S. Urban, B. Gestblom, A. Wurflinger, Mol. Cryst. Liq. Cryst., 331, 113, 1999
• 5. J. Jadzyn, G. Czechowski, R. Douali, C. Legrand, Liq. Cryst., 26, 1591, 1999
• 6. J. Jadzyn, L. Hellemans, G. Czechowski, C. Legrand, R. Douali, Liq. Cryst., 27, 613, 2000
• 7. S. Diele, Phys. Status Solidi A, 25, K183, 1974
• 8. A. Wurflinger, S. Urban, Liq. Cryst., 29, 799, 2002
• 9. P. Kedziora, J. Jadzyn, Acta Phys. Pol. A, 77, 605, 1990
• 10. S. Urban, B. Gestblom, W. Kuczyński, S. Pawlus, A. Wurflinger, Phys. Chem. Chem. Phys., 5, 924, 2003
• 11. S. Urban, B. Gestblom, S. Pawlus, Z. Naturforsch. A, 58, 357, 2003
• 12. W. Maier, G. Meier, Z. Naturforsch. A, 16, 262, 470, 1961
• 13. W.T. Coffey, Yu.P. Kalmykov, J.P. Waldron, Liq. Cryst., 18, 677, 1995
• 14. Yu.P. Kalmykov, W.T. Coffey, Liq. Cryst., 25, 329, 1998
• 15. I. Haller, Prog. Solid State Chem., 10, 103, 1975
• 16. S. Urban, J. Przedmojski, J. Czub, Liq. Cryst., 32, 619, 2005
• 17. S. Urban, K. Czupryński, R. Dabrowski, B. Gestblom, J. Janik, H. Kresse, H. Schmalfuss, Liq. Cryst., 28, 691, 2001
• 18. K. Czupryński, R. Dabrowski, J. Baran, A. Zywociński, J. Przedmojski, J. Phys. (France), 47, 1577, 1986
• 19. R. Dabrowski, J. Przedmojski, J. Baran, B. Pura, Cryst. Res. Technol., 21, 567, 1986
• 20. S. Diele, D. Jaeckel, D. Demus, H. Sackmann, Cryst. Res. Technol., 17, 1591, 1982
• 21. S. Urban, Adv. Mol. Relax. Inter. Processes, 21, 221, 1981
• 22. P. Nagrier, L.C. Pardo, J. Salud, J.L. Tamarit, M. Barrio, D.O. Lopez, A. Wurflinger, D. Mondieig, Chem. Mater., 14, 1921, 2002
• 23. S. Urban, J. Czub, R. Dabrowski, H. Kresse, Liq. Cryst., 32, 119, 2005

Identifiers

DOI

10.12693/APhysPolA.110.795