A versatile synthetic strategy for construction of large oligomers: binding and photophysical properties of a nine-porphyrin array

Mitsunobu coupling of a free base porphyrin tetraacid with four equivalents of a monohydroxy metalloporphyrin dimer leads to a highly non-polar dendritic nine-porphyrin array that is readily separated from more polar products resulting from incomplete coupling; photophysical measurements reveal an energy transfer process from the peripheral metalloporphyrins to the central free-base porphyrin unit.