Copper(II)-assisted charge transfer quenching of the excited state of a zinc(II) porphyrin complex bearing a peripheral bipyridine moiety

• A zinc(II) porphyrin dyad bearing a bipyridine moiety was synthesized.
• ET from the excited state of the porphyrin to a bpy moiety occurs in the presence of Cu2+.
• A photoinduced ET mechanism is proposed based on the transient absorption data.

A zinc(II) porphyrin complex bearing a bipyridine moiety at the periphery was synthesized. The singlet excited state of the complex was found to be quenched by Cu2 + in methanol, and the photoinduced electron transfer from the excited state of the porphyrin to the bipyridine moiety in the presence of excess Cu2 + ion was observed using a transient absorption technique. The relatively long lifetime of the charge-separated state was ascribed to the slow electron exchange reaction of Cu(II)/Cu(I) couple bound to the bipyridine unit.

A zinc(II) porphyrin dyad bearing a bipyridine moiety was synthesized. A photoinduced electron transfer from the excited state of the porphyrin complex to the bipyridine unit was observed in the presence of Cu2 + in methanol.Figure optionsDownload as PowerPoint slide