77719-31-4Relevant articles and documents
SYNTHESIS AND MESOMORPHIC PROPERTIES OF THE HOMOLOGOUS SERIES OF 4-ALKYL OR ALKOXY-4 prime -BROMO OR CYANOTOLANES.
Tinh,Pourrere,Destrade
, p. 125 - 139 (2007/10/02)
A homologous series of 4-alkyl or alkoxy-4 prime -bromo or cyanotolanes in which the alkyl group is C//4 yields C//1//0 and the alkoxy group is C//1 yields C//1//2, was prepared. Interphase transitions between solid, mesomorphic and isotropic phases were studied by hot stage microscopy and differential scanning calorimeter. The bromo compounds have a smectic polymorphism. Three pure products of cyano derivatives with the chains C//9H//1//9O, C//1//0H//2//1O amd C//1//0H//2//1 present an enantiotropic or monotropic reentrant nematic phase at atmospheric pressure. The reentrant phenomenon itself is discussed as well as the absence of correlation between T//N//A/T//N//I McMillan parameter and the heat of transition. A plot of the nematic isotropic transition temperatures against the number of carbon atoms in the alkoxy chain shows the usual odd even effect.
