INTRAMOLECULAR ENERGY MIGRATION IN POLYESTERS FROM 2,6-NAPHTHALENE DICARBOXYLIC-ACID - POLARIZATION OF FLUORESCENCE IN THE POLYMERS AND IN BICHROMOPHORIC MODEL COMPOUNDS

The fluorescence has been measured in dilute solution and in glassy poly(methyl methacrylate) for polyesters in which 2,6-naphthalene dicarboxylate is the rigid unit, and (CH2)m (m=2-6) is the flexible spacer. Bichromophoric compounds in which the same flexible spacer connects two molecules of 2-naphthoate were also studied. The anisotropy in the rigid medium demonstrates the existence of intramolecular energy migration, which becomes more important as m decreases from 6 to 2. The Forster radius is approximately 12 angstrom in the bichromophoric compounds and 14 angstrom in the polyesters.