TY - JOUR
T1 - High Oxidation State Iridium Mono-μ-oxo Dimers Related to Water Oxidation Catalysis
AU - Sharninghausen, Liam S.
AU - Sinha, Shashi Bhushan
AU - Shopov, Dimitar Y.
AU - Choi, Bonnie
AU - Mercado, Brandon Q.
AU - Roy, Xavier
AU - Balcells, David
AU - Brudvig, Gary W
AU - Crabtree, Robert H.
PY - 2016/12/14
Y1 - 2016/12/14
N2 - The highly active iridium “blue solution” chemical and electrochemical water oxidation catalyst obtained from Cp*IrL(OH) precursors (L = 2-pyridyl-2-propanoate) has been difficult to characterize as no crystal structure can be obtained because of the multiplicity of geometrical isomers present. Other data suggest complete loss of the Cp* ligand and the formation of a LIr-O-IrL unit. We have now developed a route to a series of well-defined Ir(IV,IV) mono-μ-oxo dimers, containing the closely related L2Ir-O-IrL2 unit. Unlike the catalyst, these model compounds are separable by silica gel chromatography and readily form single crystals. We report three stereoisomers with the formula ClL2Ir-O-IrL2Cl, which are fully characterized, including by X-ray crystallography, and are compared to the “blue solution”. To the best of our knowledge, these species represent the first examples of structurally characterized dinuclear μ-oxo Ir(IV,IV) compounds without metal-carbon bonds.
AB - The highly active iridium “blue solution” chemical and electrochemical water oxidation catalyst obtained from Cp*IrL(OH) precursors (L = 2-pyridyl-2-propanoate) has been difficult to characterize as no crystal structure can be obtained because of the multiplicity of geometrical isomers present. Other data suggest complete loss of the Cp* ligand and the formation of a LIr-O-IrL unit. We have now developed a route to a series of well-defined Ir(IV,IV) mono-μ-oxo dimers, containing the closely related L2Ir-O-IrL2 unit. Unlike the catalyst, these model compounds are separable by silica gel chromatography and readily form single crystals. We report three stereoisomers with the formula ClL2Ir-O-IrL2Cl, which are fully characterized, including by X-ray crystallography, and are compared to the “blue solution”. To the best of our knowledge, these species represent the first examples of structurally characterized dinuclear μ-oxo Ir(IV,IV) compounds without metal-carbon bonds.
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U2 - 10.1021/jacs.6b07716
DO - 10.1021/jacs.6b07716
M3 - Article
AN - SCOPUS:85006106428
VL - 138
SP - 15917
EP - 15926
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 49
ER -