Remarkable homology in the electronic spectra of the mixed-valence cation and anion radicals of a conjugated bis(porphyrinyl)butadiyne

The pi-radical cation and anion of the dizinc complex of a bis(triarylporphyrinyl) butadiyne, 1(+) and 1(-), respectively, display remarkably similar near- IR signatures, with intense bands near 1000 and 2500 nm, as predicted by the appropriate frontier- orbital model for inter- porphyrin coupling across the conjugated bridge.