Polymorphism of starburst molecules: methyl-substituted derivatives of 1,3,5-tris(diphenylamino)benzene

Starburst molecules based on pi -electron systems for making amorphous molecular materials, 1,3,5-tris(2-methylphenylphenylamino)benzene and 1,3,5-tris(4-methylphenylphenylamino)benzene, have been found to show polymorphism depending upon the history of heat treatment, which involves crystallization via amorphous glasses, as characterized by differential scanning calorimetry, X-ray diffraction, and polarizing microscopy.