Discotic Liquid Crystals of Organic Metal Complexes (75): Synthesis and Mesomorphism of Novel Octakisdialkoxyphenoxy-substituted Tetrapyrazinophorpyrazinato Copper(II) Complexes.

Abstract

We previously synthesized the octakisdialkoxyphenoxy-substituted phthalocyaninato copper(II) complexes 1 exhibiting seven different mesophases. In this study, we have successfully synthesized novel discotic liquid crystals of the octakisdialkoxyphenoxy-substituted tetrapyrazinophorpyrazinato copper(II) complexes 2. The molecular structural difference between 1 and 2 is very small only on the number of nitrogen atoms in the core. However, the complexes 2 exhibit only one mesophase in contrast to the previous complexes 1. The mesophase of the complexes 2 could be assigned as a novel pseudo-hexagonal columner phase Colrh(C2/m). Very interestingly, each of the complexes 2 changes color of the mesophase from purple to green with elevating temperature.