3B02 A binary system of liquid crystalline phthalocyanine and benzoporphyrin with non-peripherally attached hexyl chains : phase behavior and charge transport properties

Abstract

The blend of liquid crystalline octahexylphthalocyanine (np-C6PcH₂) and octahexyltetrabenzoporphyrin (np-C6TBPH₂) was studied on the miscibility in mesophase and their charge transport properties. Though C6PcH₂ (showing pseudo Col_h mesophase) should be immiscible to C6TBPH₂ (exbiting Col_h and Col_r phases) for the mesophases, an ambiguous situation between pseudo-Col_h and Col_r phases was seen. This indicates that these two columnar mesophases have a similar molecular order and these can be formed with a small modification of 2D arrangement of disc-shaped molecules. The carrier mobility was determined by TOF technique and the mobilities of both hole and electron are decreased in the mixtures probably due to the different energetic levels of HOMO/LUMO. The repetitive heating and cooling cycles around the clearing point give a different behavior in charge transport from that of the blend of octadecylphthalocyanine and its Zn complex.