Magyar Tudományos Akadémia
SZILÁRDTESTFIZIKAI ÉS OPTIKAI KUTATÓINTÉZET
1121
Budapest, Konkoly Thege út 29-33,  tel: 392-2212

 

SZFKI SZEMINÁRIUM

 

Valentina Domenici

 

(University of Pisa, Italy)


Deuterium NMR of "rod-like" and "banana-shaped" Liquid Crystals: Orientational Order and Dynamics

 

 

2H NMR is a powerful technique to study orientational order, molecular structure and dynamic properties of liquid crystals. The Zeeman (T1Z) and quadrupolar (T1Q) spin-lattice relaxation times of the rod-like mesogen 11EB1M7 are measured at three different Deuterium Larmor frequencies and the analysis in terms of the contribution to the dynamics of the Order Director Fluctuation (ODF) and the rotational diffusion coefficients for either the overall molecular motions (i.e. spinning and tumbling) or the internal reorientational motions is presented [1]. The comparison between NMR and Dielectric Relaxation (DR) in obtaining dynamic properties is discussed for the HAB compound [2]. The study of Deuterium NMR spectra of the selectively labeled banana-shaped mesogen ClPbis11BB [3], is presented focusing on the orientational order parameters and the geometrical properties of the central rigid core. A recent work [4] on deuterated “probe” molecules dissolved in liquid crystalline solvents is shown with the emphasis on revealing the conformational properties of banana mesogen core subunits.

 

[1] V. Domenici, M. Geppi, C. A. Veracini, R. Blinc, A. Lebar, B. Zalar, ChemPhysChem, 5, 559, 2004.

[2] V. Domenici, J. Czub, M. Geppi, B. Gestblom, S. Urban, C. A. Veracini, Liq. Cryst., 31, 91, 2004.

[3] R. Y. Dong, K. Fodor-Csorba, J. Xu, V. Domenici, G. Prampolini, C. A. Veracini, J. Phys. Chem. B, 108, 7694, 2004.

[4] V. Domenici, L.A. Madsen, E. J. Choi, E. T. Samulski, C. A. Veracini, Chem. Phys. Lett., submitted.

 

 

2004. szeptember 28. (kedd) de. 10:00

I. épület Tanácsterem

 

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