| Summary: | The synthesis and characterization of two phthalocyanine (Pc) structural isomers, <b>1</b> and <b>2</b>, in which four 2,6-di(hexyloxy)phenyl units were attached directly to the 1,8,15,22- or 1,4,15,18-positions of the Pc rings, are described. Both Pcs <b>1</b> and <b>2</b> exhibited low melting points, i.e., 120 and 130 °C respectively, due to the reduction in intermolecular π-π interaction among the Pc rings caused by the steric hindrance of 2,6-dihexyloxybenzene units. The thermal behaviors were investigated with temperature-controlled polarizing optical microscopy, differential scanning calorimetry, powder X-ray diffraction, and absorption spectral analyses. Pc <b>1</b>, having C<sub>4h</sub> molecular symmetry, organized into a lamellar structure containing lateral assemblies of Pc rings. In contrast, the other Pc <b>2</b> revealed the formation of metastable crystalline phases, including disordered stacks of Pcs due to rapid cooling from a melted liquid.
|
|---|
