Synthesis and properties of liquid crystalline 4,4 ''-dialkoxy-2 '-methyl-p-terphenyls

A new series of laterally substituted terphenyl compounds, 4,4"-dialkoxy-2'-methyl-p-terphenyls (n = 1-12), were synthesized. Their liquid crystallinities were characterized by means of polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The influence of the length of the terminal alkoxy groups on the liquid crystalline behavior was investigated. It was found that the compounds with shorter end chains (n less than or equal to 8) tended to form nematic mesophases. However, a smectic A mesophase is exhibited for those with longer end chains (9 less than or equal to n less than or equal to 12).CrystallographySCI(E)EI14ARTICLE41-5539