[Re(CO)3(5-PAN)Cl], a rhenium(i) naphthalimide complex for the visible light photocatalytic reduction of CO2

Abstract

A rhenium(I) naphthalimide complex [Re(CO)₃(5-PAN)Cl] (Re(5-PAN); 5-PAN = 1-(1,10-phenanthroline)-4-nitro-naphthalimide) was synthesized, characterized, and evaluated as a photocatalyst for CO₂ reduction. Characterization included use of MALDI-ToF mass spectrometry, FT-IR, RAMAN, ¹H and ¹³C NMR, elemental analysis, electronic absorption and emission spectroscopy, single crystal X-ray diffraction, DFT and cyclic voltammetry. Photocatalytic (406 nm) reduction of ¹³CO₂ to formate (H¹³COO) in the presence of this catalyst was tracked via¹³C NMR. Results support Re5-PAN (φ = 0.021) functioning as a catalyst for the reduction of CO₂ (maximum turn-over 48–50 at 300 equiv. triethylamine as the sacrificial electron donor).