Study of macromolecular chain dynamics in polymer complexes by time-resolved fluorescence spectroscopy

Poly(methyl methacrylate)s labeled with the anthracene fluorophore were pre pared by free radical, anionic, and coordination polymerization yielding at actic and syndiotactic polymers. Unlabeled isotactic poly(methyl methacryla te) was prepared by anionic polymerization. Time-resolved fluorescence spec troscopy was used to study polymer association in solution. The time-depend ent decays of fluorescence anisotropy show that stereocomplexation causes a n increase in rotational correlation times of anthracene fluorophores both embedded in the polymer backbone and attached at the end of the side chain of polymer molecules. The rotational correlation time of anthracene fluorop hore in dimethylformamide as a part of stereocomplex is 11.9 and 30 ns in t he side chain and embedded in the polymer backbone, respectively, and short er than 3 ns in noncomplexing solvent.