Effect of fluorine atoms in flexible chains on the phase transitions and photophysical behavior of D-π-A-type 4-alkoxy-4′-cyanodiphenylacetylene

D-pi-A-type 4-alkoxy-4 '-cyanodiphenylacetylenes bearing a decyloxy chain show a nematic liquid crystalline (LC) phase, whereas the incorporation of a semifluoroalkyl fragment results in a switch to the smectic A phase. The D-pi-A-type pi-conjugated mesogen exhibits photoluminescence, not only in solution and in the crystalline phase, but also in the molecular aggregated structure of the LC phase.

Automated summary

D-pi-A type 4-alkoxy-4'-cyanodiphenylacetylenes with a decyloxy chain exhibit a nematic liquid crystalline phase, while the introduction of a semifluoroalkyl fragment results in a switch to the smectic A phase. The D-pi-A type pi-conjugated mesogen displays photoluminescence in solution, crystalline phase, and molecular aggregated structure of the liquid crystalline phase.