An earth-abundant system for light-driven CO₂ reduction to CO using a pyridinophane iron catalyst

Abstract

A visible-light-driven earth-abundant photocatalytic system for CO2 reduction using an iron catalyst and a copper photosensitizer produces CO as a main product (TONCO = 565) with a high selectivity over H2 production (SelCO2 = 84%).

Promoting photocatalytic CO2 reduction with a molecular copper purpurin chromophore

“…Ishitani et al have shown that dimeric Cu complexes with heteroleptic diimine and phosphine ligands are effective photosensitizers to exhibit 273 turnovers of CO in 12 h 37 . The systems employed various copper diimine diphosphine complexes as the photosensitizers, Fe 37 – 39 , Co 40 , Ni 41 , or Mn 42 , 43 metal complexes as the catalysts, and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole (BIH) as the sacrificial electron donor that produced CO up to 2680 turnovers under optimal conditions 40 . While Cu diimine photosensitizers exhibit relatively higher activities in photocatalytic CO 2 reduction than organic PS, they require much higher energetic light irradiation owing to their absorption spectra centered at the UV region 36 .…”

Dehalogenation reaction photocatalyzed by homoleptic copper(i) complexes associated with strongly reductive sacrificial donors

“…[Cu(NN) 2 ] + complexes are easier easy to prepare and more stable in the long term than [Cu(PP)(NN)] + ones. 24,25 Finally, the excited state of PS Cu is sufficiently long-lived 26 to ensure reactivity with donor D.…”

An N4-Tetradentate Hydrazone Ligand That Binds in a Neutral, Mono- and Bisdeprotonated Form to Iron(II) and Zinc(II) Metal Ions

“…This is one of the few trans bond angles that is off 180 • for ZnN 4 Cl 2 complexes [51][52][53] (see the following references with examples of 180 • Cl-Zn-Cl bond angles: [54,55]). Notably, 29 out of 40 of the ZnN 4 Cl 2 complexes in the CSD database [56] actually have a cis arrangement of the chlorides (see [57,58]). All of the bond distances and bond angles in the crystal structure are comparable with similar distances in other structurally characterized six-coordinate zinc(II) complex-containing terminal chlorides [59,60].…”