Novel room-temperature thermotropic liquid crystals: synthesis and mesomorphism of gallic-perylene-gallic trimers.

Three novel gallic-perylene-gallic trimers 7, 8 and 9 were synthesized by reacting gallic amino derivatives 3, 4 or 6 with perylene tetracarboxylic anhydride in yields of 75%, 78% and 80%, respectively. Compounds 7 and 8 with soft bridging chains exhibit columnar mesophase at room temperature, but compound 9 with a rigid bridging chain exhibits no mesophase. [ABSTRACT FROM AUTHOR]