EFFECT OF COIL COLLAPSE ON PHOTON-HARVESTING POLYMERS WITH PHENANTHRENE CHROMOPHORES

Fluorescence measurements were used to explore the effect of solvent-i nduced polymer coil collapse on electronic energy transport for both m ethacrylate and methacrylic acid copolymers with pendant phenanthrene chromophores. Changes in the quantum yield and efficiency of excitatio n transport show that the efficiency of electronic energy transport to a covalently bound anthracene trap increases with coil contraction, a lthough this increase is part of a complex chain of events in which ph enanthrene-phenanthrene self-quenching plays an important role even th ough classical excimer formation is negligible. Room temperature solut ion and 77 K matrices display qualitatively similar behavior. Measurem ents for polymethacrylic acid-co/alt-poly(vinylphenanthrene) polymers in aqueous solution at room temperature and at 77 K illustrate analogo us behavior as a function of pH.