Toward efficient photomodulation of conjugated polymer emission: optimizing differential energy transfer in azobenzene-substituted PPV derivatives.

We present fluorescence studies of quenching behavior in photoaddressable azobenzene-substituted derivatives of the fluorescent conjugated polymer poly(p-phenylenevinylene) (PPV). The azobenzene side chains partially quench the PPV fluorescence, and we have shown previously that the quenching efficiency is greater when the azobenzene side chains are cis than when they are trans. This effect provides a photoaddressable means of modulating the fluorescence intensity of PPV derivatives.