title: Tracking Co(I) Intermediate in Operando in Photocatalytic Hydrogen Evolution by X-ray Transient Absorption Spectroscopy and DFT Calculation.
abstract: X-ray transient absorption spectroscopy (XTA) and optical transient spectroscopy (OTA) were used to probe the Co(I) intermediate generated in situ from an aqueous photocatalytic hydrogen evolution system, with [RuII(bpy)3]Cl2·6H2O as the photosensitizer, ascorbic acid/ascorbate as the electron donor, and the Co-polypyridyl complex ([CoII(DPA-Bpy)Cl]Cl) as the precatalyst. Upon exposure to light, the XTA measured at Co K-edge visualizes the grow and decay of the Co(I) intermediate, and reveals its Co-N bond contraction of 0.09 ± 0.03 Å. Density functional theory (DFT) calculations support the bond contraction and illustrate that the metal-to-ligand π back-bonding greatly stabilizes the penta-coordinated Co(I) intermediate, which provides easy photon access. To the best of our knowledge, this is the first example of capturing the penta-coordinated Co(I) intermediate in operando with bond contraction by XTA, thereby providing new insights for fundamental understanding of structure-function relationship of cobalt-based molecular catalysts.
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Li
authors.affiliation: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, People's Republic of China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhan
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Xiao
authors.affiliation: X-ray Sciences Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60430, United States.
authors.forename: Xiaoyi
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Synchrotron SOLEIL, L'Orme des Merisiers , Saint Aubin 91192 GIF-sur-Yvette Cedex, France.
authors.forename: Qing-Yu
authors.initials: QY
authors.lastname: Kong
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Xiang-Bing
authors.initials: XB
authors.lastname: Fan
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Wen-Qiang
authors.initials: WQ
authors.lastname: Liu
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Mao-Yong
authors.initials: MY
authors.lastname: Huang
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Huang
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Yu-Ji
authors.initials: YJ
authors.lastname: Gao
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Xu-Bing
authors.initials: XB
authors.lastname: Li
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Qing-Yuan
authors.initials: QY
authors.lastname: Meng
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Ke
authors.initials: K
authors.lastname: Feng
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Chen-Ho
authors.initials: CH
authors.lastname: Tung
authors.affiliation: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, People's Republic of China.
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Zhao
authors.affiliation: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, People's Republic of China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tao
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Li-Zhu
authors.identifier: http://orcid.org/0000-0002-5561-9922
authors.initials: LZ
authors.lastname: Wu