ABSORPTION AND LUMINESCENCE SPECTROSCOPY OF RESTRICTIVELY PROTONATED DIMERIC FORMS OF PORPHYRINS

Adsorption and luminescence properties of meso-tetra-(p-aminophenyl)po rphine (porphyrin II) associated forms exhibiting donor acceptor type intermolecular interaction have been studied in solution and in thin f ilms. Absorption properties of restrictively protonated dimeric forms of meso-tetraphenylporphine (porphyrin I) were investigated in water-d ioxane mixtures. Dimerization of the porphyrin I was shown to proceed in the presence of hydrochloric acid with increasing water content. Th e spectrum of the final product of dimerization corresponded to a doub ly protonated dimeric form. The equilibrium constant of pronated porph yrin I dimerization was determined as 1.9.10(9) M-1. The similarity of singly protonated dimeric forms of porphyrin I and polymer-bound porp hyrin II was proposed on the basis of their split spectra in the Soret region corresponding to the allowed electronic transitions.