DSC, polarizing optical microscopy and X-ray diffractometry were used to investi- gate the mesomorphic behaviour of 4-n-butyl-40-acetyl-biphenyl, which resulted to exhibit a smectic E and, possibly, a smectic K phase. Additionally, 2H NMR spec- troscopy was applied on a selectively deuterated sample to study the properties of alignment of the mesophases within a magnetic field, as well as to characterize molecular dynamics. Two motional processes were found to be active in the smectic E phase, namely fast p-flips of the benzene rings and molecular self-diffusion about the herringbone bidimensional lattice of the layers. No molecular overall diffusional motions were observed by either 2H NMR spectroscopy or dielectric relaxation measurements.
H-2 NMR and X-ray studies of a substance exhibiting crystal-like smectic phases
GEPPI, MARCO;
2007-01-01
Abstract
DSC, polarizing optical microscopy and X-ray diffractometry were used to investi- gate the mesomorphic behaviour of 4-n-butyl-40-acetyl-biphenyl, which resulted to exhibit a smectic E and, possibly, a smectic K phase. Additionally, 2H NMR spec- troscopy was applied on a selectively deuterated sample to study the properties of alignment of the mesophases within a magnetic field, as well as to characterize molecular dynamics. Two motional processes were found to be active in the smectic E phase, namely fast p-flips of the benzene rings and molecular self-diffusion about the herringbone bidimensional lattice of the layers. No molecular overall diffusional motions were observed by either 2H NMR spectroscopy or dielectric relaxation measurements.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
