Synthesis and characterization of homologous series with chiral (S)‐1‐methylpropyl terminal substituent

Homologous series of liquid crystalline azoesters and azomethine esters consisting of a (S)‐1‐methylpropyl group attached in one of the terminal positions have been synthesized and thermally characterized. All twenty‐four derivatives from both series, namely, the 4‐(4‐n‐alkoxybenzoyloxy)‐4′‐1‐(S)‐methylpropylazobenzenes and 4‐(4‐n‐alkoxybenzoyloxy)benzylidene‐4′‐1‐(S)‐methylpropylanilines exhibit mesomorphism. The lower members of the homologous series show a chiral nematic phase while the higher members show smectic C*, smectic A as well as chiral nematic mesophases. The homologues have been characterized using IR, NMR and UV‐Visible, spectroscopies, X‐ray diffraction and DSC. Their mesomorphic properties are compared with those of structurally related homologous series.