80563-43-5Relevant articles and documents
New low polar tolane cholesterics designed for infrared applications
Herman, Jakub,Kula, Przemys?aw
, p. 84231 - 84235 (2016/10/06)
We have designed, synthesized and evaluated the physical properties of new fluorinated phenyltolane based chiral liquid crystal materials with 2-methylbutyl terminal chain. The 2- or 2,6-fluorosubstitution in combination with the phenyltolane core brings surprising improvement of mesomorphic properties. The investigated compounds are characterized by a broad temperature range of the cholesteric (chiral nematic N?) phase, very low melting temperatures and easy thermal control of selective reflection in the near infrared region. The moderate helical twisting power β, high optical anisotropy and source of a blue phase make these compounds attractive for cholesteric mixture formulations.
Synthesis of Isocyano and (Haloalkynyl)Biphenyls: New Thermotropic Liquid Crystals
Bailey, A. L.,Bates, Gordon S.
, p. 417 - 428 (2007/10/02)
4-n-Alkyl-4'-cyanobiphenyls (1) have achieved widespread application as stable thermotropic liquid crystals with mesophases at room temperature.The importance of the cyano group in the liquid-crystalline behaviour of these compounds is not clearly defined.By modifying this functional group with minimal changes in molecular geometry, we have found two new classes of mesomorphs, 4-n-Alkyl-4'-isocyanobiphenyls (2) and 4-n-alkyl-4'-(haloalkynyl)biphenyls (3).The synthesis of these compounds is described.Compound 2a (R = n-butyl) is non-mesomorphic, whereas compound 2b (R = n-pentyl) is a virtual liquid crystal melting at 34-5 deg C and supercooling to a nematic phase at 30 deg C, and 2c (R = n-hexyl) is a nematic liquid crystal from 9 to 19 deg C.Compounds of structure 3 (R = n-pentyl, X = Si(CH3)3, H, CH3, Cl) are not liquid crystals.The corresponding bromo- and iodoalkynes (3, R = n-pentyl, S = Br, I) are liquid crystals with mesomorphic ranges of 88-108 deg C and 110-119 deg C, respectively.
