Description of a nematic liquid crystal based on the phthalocyanine subunit

Octasubstituted phthalocyanine derivatives have been synthesized and characterized. The mesophases were studied by optical microscopy, differential scanning calorimetry and small angle X-ray diffraction. For the 2-ethyl-hexyloxy-derivative, three transitions are observed at 170°C, 223°C and 270°C. In the latter temperature range, X-ray diffraction indicates the presence of a nematic phase which shows homeotropic orientation on untreated surfaces of a glass slide.