Synthesis and Characterization of a New Unsymmetrical Porphyrin Liquid Crystal and Its Metal Complexes

Meso-substituted unsymmetrical porphyrin liquid crystal, 5-(p-palmitoyloxy phenyl)phenyl-10,15,20-triphenyl porphyrin (PPTPPH2) and relative transition metal complexes (PPTPPM, M = Zn, Co, Mn, Cu, FeCl) were synthesized and characterized by means of elemental analysis, UV-Vis, IR, MS and 1H NMR spectroscopies. Further more, the thermal stabilities and fluorescence spectroscopy of these complexes were investigated. The liquid crystal properties were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The results reveal that the PPTPPH2 shows liquid crystalline behavior with more than one mesophase and it has a low-lying phase transition temperature, which changes from 3.9 to 73.5°C.