Stable, low-temperature discotic nematic superstructures by incorporating a laterally substituted sidearm in hexakis(phenylethynyl)benzene discogens

A new strategy for preparing room-temperature discotic nematic materials is proposed and developed stepwise to improve various discotic nematic properties. This approach replaces one sidearm of the discotic hexakis(4-hexyloxyphenylethynyl)benzene with a tris(alkoxy) sidearm, 1-ethynyl-2,3,4-tris(hexyloxybenzene), to lower transition temperatures, manipulate discotic nematic ranges, and preserve the discotic nematic superstructure while preventing column formation. Although symmetry considerations play a role in the resulting mesogenic properties, steric hindrance and van der Waals interactions are ascribed to the superior discotic nematic properties of the newly prepared discogens containing a laterally substituted sidearm.