Pyrene-Derived Iron Complexes for Efficient Photocatalytic CO₂ Reduction

Photocatalytic CO₂ reduction is an environmentally benign way for chemical fixation of CO₂. It is interesting to develop efficient photocatalyst with photosensitizing effect, through which the additional photosensitizer can be avoided. Herein, two pyrene-derived iron complexes have been synthesized for photocatalytic CO₂ reduction to CO. The molecular structures and π-π stacking behaviors of pyrene ligands are characterized by X-ray single-crystal structures and variable-temperature ¹H NMR experiments. The complexes possess good visible-light absorption abilities, florescence, and photoelectric properties. Catalyzed by the complexes, CO₂ is effectively reduced to CO without additional photosensitizer under visible-light irradiation. The structure-activity relationship of the pyrene-derived iron complexes for photocatalytic CO₂ reduction is studied by the combination of experiments and theoretical calculations.