123282-72-4Relevant academic research and scientific papers
Liquid Crystalline Characteristics of Ester Mesogens. p-Chlorophenyl p-n-alkoxycinnamates
Dave,Jayrang S.,Lohar, J. M.
, p. 25 - 27 (2007/10/02)
The newly synthesised homologous series p-chlorophenyl p'-n-alkoxycinnamates (1) can be compared with the series p-(p'-n-alkoxycinnamoyloxy)benzylidene p''-chloroanilines (2).All the homologues of series 2 are mesogens whereas in the series 1, the first two members are non-mesogens.In series 2 the first four members decompose at high temperatures.With decrease in length of the molecules of series 1 than that of series 2, the overall transition also decreases by about 150 deg.Series 2 homologues are nematogens upto the tenth carbon; from the twelfth member onwardsonly smectic mesophase is exhibited.In series 1 the nematic mesophase appears from the third member and continues upto the sixth member; from seventh member the homologues are pure smectogens.The N - I and S - I transition curves of series 1 show rising tendency - a criterion of low melting series, while in series 2 a falling tendency is shown which is indicative of high melting character.In series 2 the odd - even effect is unusually absent as against the usual alternating effect shown by series 1.From texture viewpoint both the series have common features; the nematic mesophase is threaded when it is the only phase shown and homeotropic within polymesomorphic region, whereas the smectic mesophase is focal conic fan shaped of smectic-A variety.In general series 1 is more smectogenic than series 2.
