UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Alkynyl and isocyanobiphenyls : new thermotropic liquid crystals Bailey, Austin Lou


The presence of mesomorphism in 4-n-alkyl-4'-isocyanobiphenyls 4 and 4-n-alkyl-4'-alkynylbiphenyls 5 was investigated, based on the liquid-crystallinity of the cyanobiphenyls 2 (R = n-alkyl). Compound 4 (R = n-butyl) is non-mesomorphic, whereas 4 (R = n-pentyl) is a virtual liquid crystal melting at 34-35°C and supercooling to a nematic phase at 30°C, and 4 (R = n-hexyI) is a nematic liquid crystal from 9 to 19°C. Compounds of structure 5 (R = n-pentyl, X = Si(CH₃)₃, H, CH₃, CI) are not liquid crystals. The corresponding bromo- and iodoalkynes (5, R = n-pentyl, X = Br, I) are liquid crystals with mesomorphic ranges of 88-108°C and 110-119°C, respectively. [See Thesis for Diagram]

Item Media

Item Citations and Data


For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.