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Title: Iridium Complexes with Proton-Responsive Azole-Type Ligands as Effective Catalysts for CO2 Hydrogenation

Journal Article · · ChemSusChem
 [1];  [2];  [2];  [1];  [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. National Institute of Advanced Industrial Science and Technology, Ibaraki (Japan)
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Abstract Pentamethylcyclopentadienyl iridium (Cp*Ir) complexes with bidentate ligands consisting of a pyridine ring and an electron‐rich diazole ring were prepared. Their catalytic activity toward CO 2 hydrogenation in 2.0  m KHCO 3 aqueous solutions (pH 8.5) at 50 °C, under 1.0 MPa CO 2 /H 2 (1:1) have been reported as an alternative to photo‐ and electrochemical CO 2 reduction. Bidentate ligands incorporating an electron‐rich diazole ring improved the catalytic performance of the Ir complexes compared to the bipyridine ligand. Complexes  2 , 4 , and 6 , possessing both a hydroxy group and an uncoordinated NH group, which are proton‐responsive and capable of generating pendent bases in basic media, recorded high initial turnover frequency values of 1300, 1550, and 2000 h −1 , respectively. Spectroscopic and computational investigations revealed that the reversible deprotonation changes the electronic properties of the complexes and causes interactions between pendent base and substrate and/or solvent water molecules, resulting in high catalytic performance in basic media.

Research Organization:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0012704
OSTI ID:
1405934
Alternate ID(s):
OSTI ID: 1407830
Report Number(s):
BNL-114435-2017-JA; R&D Project: CO026; KC0304030; TRN: US1702901
Journal Information:
ChemSusChem, Vol. 10, Issue 22; ISSN 1864-5631
Publisher:
ChemPubSoc EuropeCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 29 works
Citation information provided by
Web of Science

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Cited By (6)

Carbon Nitride as a Ligand: Selective Hydrogenation of Terminal Alkenes Using [(η 5 ‐C 5 Me 5 )IrCl(g‐C 3 N 4 ‐κ 2 N,N’ )]Cl journal April 2020
The Use of Cyclometalated NHCs and Pyrazoles for the Development of Fully Efficient Blue Pt II Emitters and Pt/Ag Clusters journal June 2018
Post-synthetic exchange (PSE) of UiO-67 frameworks with Ru/Rh half-sandwich units for visible-light-driven H 2 evolution and CO 2 reduction journal January 2018
CO 2 hydrogenation by phosphorus–nitrogen PN 3 P-pincer iridium hydride complexes: elucidation of the deactivation pathway journal January 2019
Development of Effective Catalysts for Hydrogen Storage Technology Using Formic Acid journal September 2018
Catalytic reactivity of an iridium complex with a proton responsive N-donor ligand in CO 2 hydrogenation to formate journal January 2018

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Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CO2 hydrogenation formic acid catalysis iridium DFT