skip to main content


Title: Striking differences in properties of geometric isomers of [Ir(tpy)(ppy)H](+): Experimental and computational studies on their hydricities, interaction with CO 2, and photochemistry

Here, we prepared two geometric isomers of [Ir(tpy)(ppy)H] +, previously proposed as a key intermediate in the photochemical reduction of CO 2 to CO, and characterized their notably different ground- and excited-state interactions with CO 2 and their hydricities using experimental and computational methods. Only one isomer, C-trans-[Ir(tpy)(ppy)H] +, reacts with CO 2 to generate the formato complex in the ground state, consistent with its calculated hydricity. Under photocatalytic conditions in CH 3CN/TEOA, a common reactive C-trans-[Ir(tpy)(ppy)] 0 species, irrespective of the starting isomer or monodentate ligand (such as hydride or Cl), reacts with CO 2 and produces CO with the same catalytic efficiency.
 [1] ;  [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [5] ;  [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States); PRESTO, Saitama (Japan); Kanagawa Univ., Yokohama (Japan)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States); Adam Mickiewicz Univ., Poznan (Poland)
  4. PRESTO, Saitama (Japan); Toyota Central R&D Labs., Inc., Aichi (Japan)
  5. Baruch College, CUNY, New York, NY (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1433-7851; R&D Project: CO026; KC0304030
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Angewandte Chemie (International Edition)
Additional Journal Information:
Journal Name: Angewandte Chemie (International Edition); Journal Volume: 54; Journal Issue: 47; Journal ID: ISSN 1433-7851
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; CO2 reduction; homogeneous catalysis; hydricity; iridium hydrides; photochemistry
OSTI Identifier: