Synthesis and Mesomorphic Properties of the 3,5-Bis-Alkoxyphenyl-Pyrazoles and-Isoxazoles

Abstract

The synthesis and measurement of physical properties using DSC, X-ray and optical methods are described for the 3,5-bis-(p-n-alkoxyphenyl)-pyrazole and 3,5-bis-(p-n-alkoxyphenyl)-isoxazole series with the carbon number of the n-alkylgroup from three to eight. The pyrazole series with longer n-alkylgroups (n = 6, 7, and 8) show the smectic A (SmA) as well as smectic C (SmC) phases. The corresponding isoxazole compounds show nematic (N) and also SmA phases. The compounds with shorter n-alkylgroups (n = 3, 4 and 5) show either nematic or SmA phases for both series respectively.