Molecular engineering of discotic nematic liquid crystals

Connecting two columnar phase forming discotic mesogens via a short rigid spacer leads to the formation of a pi-conjugated discotic dimer showing discotic nematic (N-D) phase. Attaching branched-alkyl chains directly to the core in hexaalkynylbenzene resulted in the stabilisation of N-D phase at ambient temperature. Pentalkynylbenzene derivatives possessing a combination of normal and branched-alkoxy chains display a very broad N-D phase which is stable well below and above the room temperature.