The nematic discotic phase in materials containing a siloxane core

The synthesis of a series of novel multipodes based on disc-shaped mesogens with a siloxane core is described. Their phase behaviour is characterised and compared to the liquid crystalline properties of the discolic molecules without the siloxane moieties. We observed that incorporation of the siloxane group results in a strong decrease of all transition temperatures, resulting for one series in (close to) room temperature nematic mesophases. In a second series all liquid crystalline properties were suppressed. Introduction of nematic phases was accomplished via the formation of charge transfer complexes.