Absorption and fluorescence spectra of solutions of Zn-5-(4-vinylphenyl)-10,15,20-triphenylporphyrin-methyl methacrylate copolymers

Luminescent properties of solutions of Zn-5-(4-vinylphenyl)-10,15,20-triphe nylporphyrin-methyl methacrylate copolymers are studied. Absorption and flu orescence spectra as well as dependences of the fluorescence quantum yield on the mole fraction of porphyrin groups are measured in various solvents w ith different dielectric constants. The effect of fluorescence concentratio n quenching is found, which decreases with increasing solvent polarity. The mechanism of concentration quenching is discussed in terms of the formatio n of nonluminescent dimers of static quenching pairs. The absorption spectr a of copolymers reveal a new long-wavelength band, which was assigned to a fluorescent dimer. The fluorescence spectrum of a copolymer excited in the absorption band edge differs from those of the porphyrin monomer and copoly mer observed upon excitation in the Q-band maximum.