DONOR-ACCEPTOR INTERACTIONS IN PORPHYRIN ASSOCIATES IMMOBILIZED IN BIPHILIC COPOLYMER

Interactions between associated aminoporphyrins in solution and porphy rin covalently bound to a copolymer of methacrylic acid and N-hexadecy lmethacryloilamide were investigated using absorption, emission and vi brational spectroscopy. Two types of associated porphyrin species were revealed in the fluorescence spectra and in the resonance Raman spect ra by selective excitation of porphyrins. Following excitation at 441. 6 and 514.5 nm the Raman scattering data differ in the region 300-1600 cm-1 for associated species and are similar for monomeric meso-tetrap henylporphine. Second derivative absorption spectra indicate that the association of porphyrins does not destroy the electronic structure of the porphyrin macrocycle although it strongly disturbs the pi-electro n orbitals. A study of porphyrins in solution and thin films provides evidence for donor-acceptor interaction between associated porphyrins. The interaction observed is discussed.