Synthesis of porphyrins bearing uracyl groups and their assembly induced by melamine derivatives

Self-assembled porphyrins via noncovalent bonding have attracted wide-ranging researchers in material science. We reported herein the synthesis of the tetraphenyl porphyrin derivatives bearing uracyl groups as acceptor-donor-acceptor (ADA) type hydrogen bonding units, through the condensation of 5,10- or 5,15-bis (3-amino-4-ethylhexylphenyl) porphyrin derivatives with 6-carboxyuracyl derivatives. When two porphyrins having uracyl groups at the different substituted positions were respectively mixed with a melamine derivative in benzene, ¹H NMR spectra showed that the 5,15 substituted uracyl porphyrin formed a hydrogen-bonded suprastructure with the melamine derivative as a complementary molecule to the uracyl moiety, although the other 5,10-substituted uracylporphyrin could not form such a structure. The SEM observation indicated that the mixture with the 5,15-substituted uracyl porphyrin and the melamine with long alkyl chains formed a sheet-like structure.