Asymmetrically substituted liquid‐crystalline phthalocyanines and side‐chain polymers derived from them

Abstract

Abstract Asymmetrically substituted, liquid‐crystalline phthalocyanines were synthesized. They contain one methoxy, six dodecyloxy and one acryloyloxy‐ or methacryloyloxydodecyloxy groups. The latter functions were polymerized under free radical conditions to give polymers with molecular weights between 9000 and 47000. The aggregation behaviour of the phthalocyanines in the polymer side chains was studied in solution by absorption and fluorescence spectroscopy. An enhanced intramolecular interaction between the phthalocyanines was observed. In the solid state this interaction is reflected in the spontaneous formation of a columnar structure. The polymers, however, do not display liquid‐crystalline behaviour. Temperature‐dependent luminescence measurements (at 4,2 – 300 K) were performed and the results are explained by the presence of an efficient energy migration process through the stacked phthalocyanine units.