Energy Transport along Conjugated Polymer Chains: Through‐Space or Through‐Bond?

On the basis of a quantum‐chemical description of the lowest singlet electronic excited states of bi‐chromophoric model systems, we have disentangled the through‐bond (TB) from the through‐space (TS) contributions to the electronic interactions mediating energy hopping in rigid‐rod conjugated polymers. While TB interactions lead to significant mixing between local and charge‐transfer excitations in the ground‐state (acceptor) configuration, this effect is reduced in the excited‐state (donor) configuration as a result of the self‐confinement induced by geometric relaxation phenomena. Thus, an improved Förster‐type hopping model retaining only long‐range TS contributions between donors and acceptors but accounting for excited‐state delocalization among acceptors (possibly driven by TB interactions) appears as a minimal model to treat excitation transport along polymer chains.