Tristriazolotriazines with Azobenzene Arms - Acidochromic Dyes and Discotic Liquid Crystals

Abstract

Tristriazolotriazines with azobenzene substitution and peripheral alkoxy- or alkylamino chains were prepared from the corresponding aryltetrazoles and cyanuric chloride. These star-shaped dyes are highly acidochromic. Alkoxy-substitution allows reversible trans-cis photoswitching. Compounds with a 3,4-dialkoxy substitution are discotic liquid crystals that form broad and stable thermotropic mesophases. The thermal behavior was studied by DSC and polarizing optical microscopy.