Site Isolation Leads to Stable Photocatalytic Reduction of CO2 over a Rhenium-Based Catalyst

A porous organic polymer incorporating [(alpha-diimine)Re(CO)(3)Cl] moieties was produced and tested in the photocatalytic reduction of CO2, with NEt3 as a sacrificial donor. The catalyst generated both H-2 and CO, although the Re moiety was not required for H-2 generation. After an induction period, the Re-containing porous organic polymer produced CO at a stable rate, unless soluble [(bpy)Re(CO)(3)Cl] (bpy = 2,2'-bipyridine) was added. This provides the strongest evidence to date that [(alpha-diimine)Re(CO)(3)Cl] catalysts for photocatalytic CO2 reduction decompose through a bimetallic pathway.