Preliminary communication Enantiotropic and monotropic transitions of the discotic mesogen 5,10,15,20-tetrakis(4-n-dodecylphenyl)porphyrin under pressure

The crystal and mesophase transitions of the discotic material 5,10,15,20-tetrakis(4- n-dodecylphenyl)porphyrin have been studied by high pressure DTA and wide angle X-ray diffraction. At lower pressures, the discotic lamellar (DL) phase is enantiotropic, but at higher pressures above a critical point determined as 240MPa and 170 C the DL phase is monotropic.