Cyanobiphenyl homologous series

Shirakawa, T, Hayakawa, T., and Tokuda, T, Pressure-volume-temperahire relations and isotropic-nematic phase transitions for a 4 -n-alkyl-4-cyanobiphenyl homologous series, J. Phys. Chem., 87,1406-1408 (1983). 

Frost and Lalanne [77] have performed similar experiment in MBBA. The molecular theory of orientational fluctuations and Kerr effect can be found in the work of Flytzanis and Shen [76]. The optical Kerr effect in the alkoxyazoxybenzene homologous series is reported by Hanson et al. [78] and the same technique was used by Coles [79] in the studies of the pretransitional dynamics of alkyl cyanobiphenyl homologs. 

The results of these calculations for the N-I transition temperature based on the continuous torsional model are shown in Fig. 26 for the methylene linked cyanobiphenyl dimers with the spacer containing from 3 to 18 atoms. For ease of comparison, the transition temperatures have been scaled with the value for the sixth member of the homologous series. The results reveal that the alternation in is rapidly attenuated with increasing spacer length and that for spacers containing more than about 11 atoms, the alternation in Tn-i is essentially... 

The first report on the liquid crystalline properties of these compounds was published by Gray and Mosley [44] in 1976. The series of 4 -n-alkyl-4-cyanobiphenyls (CBn) have been widely studied by different methods due to their readily accessible nematic ranges around room temperature. The compounds have the phase sequences crystal-nematic-isotropic for CBS, CBIO, and monotropic nematic for CBS, CB4 crystal-smectic A-nematic-isotropic for CB9 crystal-smectic A-isotropic for CBll. The lower homologous CB2 is nonmesogenic. The general chemical structure of the compounds CBn is presented in Fig. 1. 

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