Calamitic-discotic dimers

Fig. la-e. Sketches of the possible molecular architectures for liquid crystal dimers a symmetric calamitic dimer b non-symmetric calamitic dimer c symmetric discotic dimer d non-symmetric discotic-calamitic dimer e laterally linked symmetric dimer. Ellipses represent rod-like mesogenic groups, circles disc-like mesogenic units and wavy lines denote the flexible spacers... 

Non-Symmetric Discotic-Calamitic Liquid Crystal Dimers. 172... 

This experimental difficulty was overcome by simulating the behaviour of a model system and a biaxial nematic phase was indeed obtained [122], One way by which the problem of phase separation could be solved experimentally was suggested by Fletcher and Luckhurst and involved covalently linking a rod-like and disc-like unit via a flexible spacer yielding a non-symmetric discotic-calamitic liquid crystal dimer [123] ... 

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