Abstract: With the aim of developing new oligothiophene-based liquid crystals involving hydrogen bonding‚new terthio-phene derivatives containing an alkylamide group‚N‚N’-dialky- l5‚5”-dibromo-2‚2’：5’‚2”-terthiophene-4‚4”-dica-rboxamide （DNC n DBr3T‚n＝5‚8‚16‚18）‚were designed and synthesized‚and their thermal behavior were examined．While DNC n DBr3T compounds with n＝8‚16‚18were found to form smectic A phase．It is shown that the alkyl chain length greatly affects liquid crystal phase formation．The absence of liquid crystallinity in the corresponding ester derivatives suggests that intermolecular hydrogen bonding also plays a role in the formation of liquid crystal phase in the DNC n DBr3T system．The electrical ‚opticaal and gelation
properties of DNC n DBr3T（n ＝8‚16‚18） were reported．

Key words:  oligothiophene derivative, liquid crystal, intermolecular hydrogen bonding, liquid crystal gel