Author: Kutsumizu Shoichi
Publisher: Taylor & Francis Ltd
ISSN: 0267-8292
Source: Liquid Crystals, Vol.33, Iss.1, 2006-01, pp. : 75-84
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Abstract
The cubic phase structure of 4'- n -hexadecyloxy-3'-cyanobiphenyl-4-carboxylic acid (ACBC-16) was examined by X-ray diffraction. Unlike the octadecyloxy homologue showing an Im 3 m -type cubic phase, the cubic phase of ACBC-16 was of Ia 3 d type, both on heating and on cooling, similarly to the corresponding nitro-substituted analogue (ANBC-16). The lattice dimension a at 453 K was a = 11.0 nm, 2.5% larger than the value for ANBC-16 and rather close to the value of ANBC-17 or -18. It is expected that the appearance of the cubic phase type, as a function of the number of carbon atoms n in the alkoxy chain in the ACBC- n series, is essentially the same as in the ANBC- n series, but shifted towards shorter n by 1 or 2. In the latter ANBC- n series, the cubic phase type is Ia 3 d for 15? n ?18, while an Im 3 m type is formed for 19? n ?21, both on heating and on cooling.