A self-assembled light-harvesting array of seven porphyrins in a wheel and spoke architecture

[GRAPHICS] A shape persistent cyclic array of six zinc porphyrins provides an effective host for a dipyridyl-substituted free base porphyrin, yielding a self-assembled structure for studies of light harvesting. Energy transfer occurs essentially quantitatively from uncoordinated to pyridyl-coordinated zinc porphyrins in the cyclic array. Energy transfer from the coordinated zinc porphyrin to the guest free base porphyrin is less efficient (Phi(trans) similar to 40%) and is attributed to a Forster through space process.