Study of relation between liquid crystal properties and molecular structure of halogenated benzyl alcohol ester derivative

摘要

Comparison among the structurally similar analogous or isomeric novel homologous series of presently investigation is discussed with a view to understand the effect and relation between molecular structure in respect of molecular size, geometrical shape, molecular polarity and polarizability etc as emerged from changing molecular rigidity and flexibility which is played by terminal or central bridge to inducing liquid crystal property and the specific degree of mesomorphism of a substance. Novel series of study consists of three phenyl rings, two central bridges -COO-, -CH=CH-COO-, -COO-CH2-, -CH=CH-COO-CH2- with common left n-alkoxy (-O-CnH2n + 1) left terminal group which vary from homologue to homologue in the same series and varying tail end group -Cl and -Br. Novel members of series were selectively characterized and confirmed by elemental analysis, IR spectra, (HNMR)-N-1 spectra, mass spectra, POM, textures of smectic or/and nematic phase by miscibility method etc. Totally 66 novel compounds were synthesized and 55 compounds were to be found liquid crystal (LC) in nature with different degree of mesomorphism depending upon changing molecular structure in respect of their tailed flexible end groups or central bridges.