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 we synthesized two pyrene-derived iron complexes for photocatalytic CO2 reduction to CO. The molecular structures and π-π stacking behaviors of pyrene ligands were 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 can be 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 was studied by the combination of experiments and theoretical calculations.