Phase transitions of long chain esters of meso-tetrakis(para-carboxyphenyl)porphyrin

Abstract
Several long chain esters of meso-tetrakis(para-carboxyphenyl)porphyrin, and two of their metal complexes (Cu, Zn) have been prepared and characterized. Each of them exhibits at least one thermotropic phase transition below the clearing point to the isotropic liquid, but no definitive evidence of liquid crystallinity has been found by differential scanning calorimetry, optical microscopy, or X-ray diffraction.