Discotic liquid crystals of transition metal complexes 27: supramolecular structure of liquid crystalline octakisalkylthiophthalocyanines and their copper complexes

A series of octakisalkylthiophthalocyanines, (CnS)8PcH2 (n = 8, 10, 12, 16), and their copper(II) complexes, (CnS)8PcCu (n = 8, 10, 12, 16), have been synthesized. Their mesomorphism and supramolecular structures have been investigated by using differential scanning calorimetry, polarizing microscopy, temperature-dependent X-ray diffraction technique and temperature-dependent electronic spectroscopy. From the X-ray diffraction and electronic spectral results, it was revealed that each of the compounds has a Dh mesophase in which columnar structures the molecules form a mixture of the parts of aggregated dimers and monomers. The shapes of dimers are discussed by exciton coupling theory (Kasha's rule).