Shingo Hasegawa
;
Koji Harano
(National Institute for Materials Science
)
;
Ken Motokura
説明:
(abstract)Noble-metal-based bimetallic oxide clusters are promising novel catalysts. In this study, we developed carbon-supported RhRu bimetallic oxide clusters (RhRuOx/C) with a mean diameter of 1.2 nm, which showed remarkable catalytic activity for the cross-dehydrogenative coupling (CDC) of arenes and carboxylic acids with O2 as the sole oxi-dant. RhRu bimetallic oxide cluster formation was confirmed by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy with energy-dispersive X-ray spectroscopy and synchrotron X-ray absorp-tion spectroscopy. Kinetic isotope and substituent effects indicated that arene C–H bond cleavage was the rate-determining step and proceeded via electrophilic concerted metalation–deprotonation mechanism, with a carbox-ylate as an internal base. Density functional theory calculations supported the proposed mechanism and indicated that the active center for C–H bond activation was Rh(V) rather than Rh(III), while Ru enhanced the electrophilicity of the Rh(V) site by decreasing the negative charge of the surrounding oxygen atoms. Electron-rich arenes showed rela-tively high reactivity for RhRuOx/C-catalyzed CDC reaction, and both aliphatic and aromatic carboxylic acids were applicable to the reaction. The RhRuOx/C catalyst is promising for the CDC reaction of arenes and carboxylic acids to produce aryl esters. This work will promote the development of noble-metal-based bimetallic oxide clusters for C–H bond activation reactions.
権利情報:
キーワード: catalyst, bimetallic nanoparticles, scanning transmission electron microscopy, cross-dehydrogenative coupling
刊行年月日: 2024-07-17
出版者: American Chemical Society (ACS)
掲載誌:
研究助成金:
原稿種別: 著者最終稿 (Accepted manuscript)
MDR DOI: https://doi.org/10.48505/nims.4689
公開URL: https://doi.org/10.1021/jacs.4c03467
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更新時刻: 2025-06-06 08:30:18 +0900
MDRでの公開時刻: 2025-06-06 08:20:15 +0900
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