Abstract A homologous series of “fraternal twin” molecules consisting of relatively short and relatively long mesogenic units connected by a flexible spacer group and flexible chains as the terminal groups was synthesized in an attempt to form a non-chiral longitudinal ferroelectric smectic phase. The shorter of the two mesogenic units consisted of a 4-alkyl/alkoxy substituted biphenyl ester; the longer a terbenzoate group. Mesomorphic properties were determined by hot-stage polarizing microscopy and DSC. Several smectic phases were observed as well as nematic phases. Characterization of the smectic phases by microscopic textures is discussed.