(Invited) DAN Assisted Formation of Charge Transfer Complex from Highly Charged Fullerenes and Conjugated Polymer

Water-soluble, same charged, cationic conjugated poly(phenylenevinylene) (PPV) and cationic fullerenes were complexed with negatively charged single stranded DNA and double stranded DNA via electrostatic and pi-pi interactions. The photoinduced charge transfer complex (PPV/DNA/C₆₀) has a charge transfer and separation efficiencies at least comparable to those observed from oppositely charged, cationic PPV and anionic fullerene. DNA serves as a template that straightens the PPV chain conformation which leads to an enhanced quantum yield. Meanwhile, DNA allows incorporation of C₆₀ by overcoming the electrostatic repulsion between PPV and C₆₀. While oppositely charge donor and acceptor molecules feature charge transfer in the form of static quenching, for DNA-assisted charge transfer complexes, the charge transfer proceeds as a combination of static and dynamic quenching for ssDNA and purely dynamic for dsDNA.