In this work, the rotational-diffusion coefficients D-parallel to and D-perpendicular to for the ferroelectric smectogen (+)-(S)-4-[4'-(1-methylheptyloxy)] biphenyl 4-(10-undecenyloxy)benzoate have been studied by means of H-2 NMR spectroscopy in the smectic C* phase, using a new theoretical approach (Domenici,V.; Geppi, M.; Veracini, C. A. Chem. Phys. Lett. 2003, 382, 518). The analysis of spin-lattice relaxation times has been performed in terms of the diffusional. constant and the activation energy of the internal and overall molecular-reorientational motions, and the results are compared to the smectic A (SmA) phase. Moreover, from the H-2 NMR data in the SmA phase, the dielectric permittivity and the dielectric relaxation time functions tau(mn)(L) are investigated using a theoretical approach. The longitudinal and transverse components of the real R chi(gamma)(omega) and imaginary chi(gamma)(omega) (gamma = parallel to, perpendicular to) parts of the complex susceptibility tensor and the nematic-like rotational-viscosity coefficients, lambda(2) and lambda(5), are calculated.

Molecular Dynamics in the Smectic A and C* phases in a long-chain ferroelectric liquid crystal: 2H NMR, dielectric properties, and a theoretical treatment

DOMENICI, VALENTINA;GEPPI, MARCO;VERACINI, CARLO ALBERTO
2005-01-01

Abstract

In this work, the rotational-diffusion coefficients D-parallel to and D-perpendicular to for the ferroelectric smectogen (+)-(S)-4-[4'-(1-methylheptyloxy)] biphenyl 4-(10-undecenyloxy)benzoate have been studied by means of H-2 NMR spectroscopy in the smectic C* phase, using a new theoretical approach (Domenici,V.; Geppi, M.; Veracini, C. A. Chem. Phys. Lett. 2003, 382, 518). The analysis of spin-lattice relaxation times has been performed in terms of the diffusional. constant and the activation energy of the internal and overall molecular-reorientational motions, and the results are compared to the smectic A (SmA) phase. Moreover, from the H-2 NMR data in the SmA phase, the dielectric permittivity and the dielectric relaxation time functions tau(mn)(L) are investigated using a theoretical approach. The longitudinal and transverse components of the real R chi(gamma)(omega) and imaginary chi(gamma)(omega) (gamma = parallel to, perpendicular to) parts of the complex susceptibility tensor and the nematic-like rotational-viscosity coefficients, lambda(2) and lambda(5), are calculated.
2005
Domenici, Valentina; Geppi, Marco; ZAKHAROV A., V; Veracini, CARLO ALBERTO
File in questo prodotto:
File Dimensione Formato  
JPCB2005_109_18369.pdf

non disponibili

Tipologia: Documento in Post-print
Licenza: Importato da Ugov Ricerca - Accesso privato/ristretto
Dimensione 166.3 kB
Formato Adobe PDF
166.3 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/199030
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 14
  • ???jsp.display-item.citation.isi??? 13
social impact