Accessing Molecular Dimeric Ir Water Oxidation Catalysts from Coordination Precursors.

Autor:	Hu G; Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States.; Energy Sciences Institute, Yale University, 520 West Campus Drive, West Haven, Connecticut 06516, United States., Troiano JL; Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States.; Energy Sciences Institute, Yale University, 520 West Campus Drive, West Haven, Connecticut 06516, United States., Tayvah UT; Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States.; Energy Sciences Institute, Yale University, 520 West Campus Drive, West Haven, Connecticut 06516, United States., Sharninghausen LS; Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States., Sinha SB; Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States., Shopov DY; Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States., Mercado BQ; Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States., Crabtree RH; Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States.; Energy Sciences Institute, Yale University, 520 West Campus Drive, West Haven, Connecticut 06516, United States., Brudvig GW; Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States.; Energy Sciences Institute, Yale University, 520 West Campus Drive, West Haven, Connecticut 06516, United States.
Jazyk:	angličtina
Zdroj:	Inorganic chemistry [Inorg Chem] 2021 Sep 20; Vol. 60 (18), pp. 14349-14356. Date of Electronic Publication: 2021 Sep 03.
DOI:	10.1021/acs.inorgchem.1c02025
Abstrakt:	One ongoing challenge in the field of iridium-based water oxidation catalysts is to develop a molecular precatalyst affording well-defined homogeneous active species for catalysis. Our previous work by using organometallic precatalysts Cp*Ir(pyalk)OH and Ir(pyalk)(CO) 2 (pyalk = (2-pyridyl)-2-propanolate) suggested a μ-oxo-bridged Ir dimer as the probable resting state, although the structure of the active species remained elusive. During the activation, the ligands Cp* and CO were found to oxidatively degrade into acetic acid or other products, which coordinate to Ir centers and affect the catalytic reaction. Two related dimers bearing two pyalk ligands on each iridium were crystallized for structural analysis. However, preliminary results indicated that these crystallographically characterized dimers are not active catalysts. In this work, we accessed a mixture of dinuclear iridium species from a coordination precursor, Na[Ir(pyalk)Cl 4 ], and assayed their catalytic activity for oxygen evolution by using NaIO 4 as the oxidant. This catalyst showed comparable oxygen-evolution activity to the ones previously reported from organometallic precursors without demanding oxidative activation to remove sacrificial ligands. Future research along this direction is expected to provide insights and design principles toward a well-defined active species.
Databáze:	MEDLINE
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