Effect of polymer additives on magnetic modulation of the yield of products of recombination of triplet radical ion pairs in electron phototransfer between N,N-Dimethylaniline and pyrene. 2. Poly-N-tert-butylacrylamide in methanol

Abstract

The effect of a magnetic field on the intensity of delayed fluorescence of pyrene excimers formed during evolution of pyrene — N,N-dimethylaniline radical ion pairs (RIP) in methanol containing glycerol or poly-N-tert-butylacrylamide was comparatively investigated by laser strobe fluorometry. Different methods of restricting the molecular mobility of the reagents cause different values of the magnetic effect with the same microviscosity measured with the spin probe orientational correlation time. This result contradicts the data obtained previously for mixtures with polyacrylamide and can be explained with the data on cross-linking of the polymer-containing solution. The viscosity of the microenvironment of the RIP partners is ≈ 10 times higher than the viscosity of the solvent. The presence of a maximum on the curve of the change in the magnetic effect in restriction of the molecular mobility was attributed to an increase in the lifetime of the radical pair and a change in the ratio of the relaxation rates and yield of radicals in bulk.