Tracking C-H activation with orbital resolution

• 成果类型: Article
• 署名作者: Jay, Raphael M.; Banerjee, Ambar; Leitner, Torsten; Wang, Ru-Pan; Harich, Jessica; Stefanuik, Robert; Wikmark, Hampus; Coates, Michael R.; V. Beale, Emma; Kabanova, Victoria; Kahraman, Abdullah; Wach, Anna; Ozerov, Dmitry; Arrell, Christopher; Johnson, Philip J. M.; Borca, Camelia N.; Cirelli, Claudio; Bacellar, Camila; Milne, Christopher; Huse, Nils; Smolentsev, Grigory; Huthwelker, Thomas; Odelius, Michael; Wernet, Philippe
• 署名单位: Uppsala University; University of Hamburg; Stockholm University; Swiss Federal Institutes of Technology Domain; Paul Scherrer Institute; Polish Academy of Sciences; Institute of Nuclear Physics - Polish Academy of Sciences; European XFEL; Uppsala University; Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; United States Department of Energy (DOE); Pacific Northwest National Laboratory
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12735
• DOI: 10.1126/science.adf8042
• 发表日期: 2023-06-02
• 页码: 955-960
• 关键词: transition-metal-complexes; bond activation; electronic-structure; oxidative addition; alkane complex; absorption; photochemistry; spectroscopy; DYNAMICS; valence

摘要

Transition metal reactivity toward carbon-hydrogen (C-H) bonds hinges on the interplay of electron donation and withdrawal at the metal center. Manipulating this reactivity in a controlled way is difficult because the hypothesized metal-alkane charge-transfer interactions are challenging to access experimentally. Using time-resolved x-ray spectroscopy, we track the charge-transfer interactions during C-H activation of octane by a cyclopentadienyl rhodium carbonyl complex. Changes in oxidation state as well as valence-orbital energies and character emerge in the data on a femtosecond to nanosecond timescale. The x-ray spectroscopic signatures reflect how alkane-to-metal donation determines metal-alkane complex stability and how metal-to-alkane back-donation facilitates C-H bond cleavage by oxidative addition. The ability to dissect charge-transfer interactions on an orbital level provides opportunities for manipulating C-H reactivity at transition metals.