Diazotization of 5-(4 '-Aminophenyl)-10,15,20-tris(4 '-sulfophenyl) porphine in Water. Synthesis of Conjugate with H-Acid

Water-soluble 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfophenyl)porphine was obtained by three-stage synthesis from tetraphenylporphyrin under conditions of supramolecular control of regioselectivity of nitration and sulfonation reactions. In acidic medium (pH approximate to 2) the trianion H2P(PhNH2)(PhSO3-)(3) is protonated at the porphyrin platform and the amino group to form the aqua complex of the zwitterion [H4P2+(PhNH3)(PhSO3H)(PhSO3-)(2)](H2O)(2), which is self-assembled into porphyrin nanotubes (FWTs), the outer surface of which is covered with positively charged groups -PhNH3+, and the inner surface with electroneutral groups -PhSO3H. By the action of nitrous acid, stable diazotized PAITs were obtained. Supramolecular self-assembly inhibits the azo coupling reaction of H4P2+(PhN2+)(PhSO3H)(PhSO3-)(2) ( )tectons with H-acid in an acidic medium. H-Conjugate was obtained by azo coupling in an alkaline medium (pH approximate to 10), where diazotized PNTs are destroyed with formation of the diazocompound H2P(PhN2+)(PhSO3-)(3). The resulting product was characterized by H-1 NMR, MS MALDI-TOF and UV-Vis spectra.