Structural and Spectroscopic Characterization of Reaction Intermediates Involved in a Dinuclear Co–Hbpp Water Oxidation Catalyst

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• 作者：Carolina Gimbert-Suriñach ; Dooshaye Moonshiram ; Laia Francàs ; Nora Planas ; Varinia Bernales ; Fernando Bozoglian ; Alexander Guda ; Lorenzo Mognon ; Isidoro López ; Md Asmaul Hoque ; Laura Gagliardi ; Christopher J. Cramer ; Antoni Llobet
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：November 30, 2016
• 年：2016
• 卷：138
• 期：47
• 页码：15291-15294
• 全文大小：346K
• ISSN：1520-5126

文摘

An end-on superoxido complex with the formula {[Co^III(OH₂)(trpy)][Co^III(OO^•)(trpy)](μ-bpp)}⁴⁺ (3⁴⁺) (bpp^– = bis(2-pyridyl)-3,5-pyrazolate; trpy = 2,2′;6′:2″-terpyridine) has been characterized by resonance Raman, electron paramagnetic resonance, and X-ray absorption spectroscopies. These results together with online mass spectrometry experiments using ¹⁷O and ¹⁸O isotopically labeled compounds prove that this compound is a key intermediate of the water oxidation reaction catalyzed by the peroxido-bridged complex {[Co^III(trpy)]₂(μ-bpp)(μ-OO)}³⁺ (1³⁺). DFT calculations agree with and complement the experimental data, offering a complete description of the transition states and intermediates involved in the catalytic cycle.