A series of N,N'-(2-chloroterephthalylidene)bis(4-n-alkylaniline)s (CTBAAs) were prepared and their mesomorphic behaviour characterized. None of the homologues showed smectic behaviour, but nematic behaviour with broad mesophases and rather low melting points was seen. The mesomorphic behaviour was compared with that of N,N'-(terephthalylidene) -bis(4-n-alkylaniline)s (TBAAs) and 4,4-bis-(n-alkylbenzal)-2-chloro-1,4-phenylenediamines (BACPDs). An X-ray diffraction analysis of N,N'-(2-chloro-terephthal)bis(4-n-butylaniline) (CTBBA) showed that the molecules were packed in crystals forming a staggered arrangement called an 'imbricated structure'.