In this thesis, the liquid crystal properties of dimers of pentakis(phenylethynyl)benzene were studied. Compounds A to D, synthesized by former members, are further purified to obtain complete spectroscopic and liquid crystalline property data. Disc dimers with alkoxy chains tend to form the discotic nematic phase. Disc dimers with alkyl chains are prone to form the columnar phase. A new disc dimer E with longer alkyl chains has been prepared to show lower transition temperatures.