Fluorescence Enhancement of a Porphyrin–Viologen Dyad by Pseudorotaxane Formation with Cucurbit[7]uril

Dicationic viologen species are known to form strong supramolecular complexes with cucurbit[7]uril, as well as participate in electron-transfer processes with donor systems. We describe the use of cucurbit[7]uril to modulate the electron transfer between a hybrid porphyrin (donor) and a viologen (acceptor) dyad. The X-ray crystal structure of these hybrids reveals the formation of 1D coordination polymers held together through zinc coordination in the solid state.