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.
Autori interni: | ||
Autori: | Calucci L; Geppi M; Przedmojski J; Czub J; Urban S; Dabrowski R | |
Titolo: | H-2 NMR and X-ray studies of a substance exhibiting crystal-like smectic phases | |
Anno del prodotto: | 2007 | |
Digital Object Identifier (DOI): | 10.1080/15421400701205636 | |
Appare nelle tipologie: | 1.1 Articolo in rivista |