Resonance energy transfer dynamics in hydrogen-bonded oligo-p-phenylenevinylene nanostructures

Oligo-p-phenylenevinylene (OPV) materials monofunctionalised with ureido-s-triazine form chiral, helical stacks in dodecane soln. Here, we investigate resonance energy transfer dynamics in supramol. stacks of OPVs consisting of three Ph rings (MOPV3) doped with similar oligomers contg. four Ph rings (MOPV4). Broad spectral overlap between the MOPV3 fluorophores and MOPV4 chromophores results in efficient energy transfer from MOPV3 to MOPV4. We observe resonance energy transfer following two distinct regimes. The first is evident by growth of MOPV4 photoluminescence on a timescale of .apprx.50 ps, mediated by rapid exciton diffusion in MOPV3 within the stack. In the second regime, dynamics of localised excitons on nanosecond timescales are dominated by direct resonance energy transfer to MOPV4 chromophores. Global anal. of the photoluminescence decay of MOPV3 in blends with varying MOPV4 compn. on times .gtorsim.2 ns is consistent with quasi-one-dimensional resonance energy transfer with Foerster radius of 8 nm.