title: Photocatalytic Reduction of CO2 with Re-Pyridyl-NHCs.
abstract: A series of Re(I) pyridyl N-heterocyclic carbene (NHC) complexes have been synthesized and examined in the photocatalytic reduction of CO2 using a simulated solar spectrum. The catalysts were characterized through NMR, UV-vis, cyclic voltammetry under nitrogen, and cyclic voltammetry under carbon dioxide. The complexes were compared directly with a known benchmark catalyst, Re(bpy) (CO)3Br. An electron-deficient NHC substituent (PhCF3) was found to promote catalytic activity when compared with electron-neutral and -rich substituents. Re(PyNHC-PhCF3) (CO)3Br was found to exceed the CO production of the benchmark Re(bpy) (CO)3Br catalyst (51 vs 33 TON) in the presence of electron donor BIH and photosensitizer fac-Ir(ppy)3. Importantly, Re(PyNHC-PhCF3) (CO)3Br was found to function without a photosensitizer (32 TON) at substantially higher turnovers than the benchmark catalyst Re(bpy) (CO)3Br (14 TON) under a solar simulated spectrum.
authors.affiliation: Department of Chemistry and Biochemistry, University of Mississippi , 405 Coulter Hall, University, Mississippi 38677, United States.
authors.forename: Aron J
authors.initials: AJ
authors.lastname: Huckaba
authors.affiliation: Department of Chemistry and Biochemistry, University of Mississippi , 405 Coulter Hall, University, Mississippi 38677, United States.
authors.forename: Emily Anne
authors.initials: EA
authors.lastname: Sharpe
authors.affiliation: Department of Chemistry and Biochemistry, University of Mississippi , 405 Coulter Hall, University, Mississippi 38677, United States.
authors.forename: Jared H
authors.initials: JH
authors.lastname: Delcamp