Direct evidence for a carbon-carbon one-electron σ-bond

• 成果类型: Article
• 署名作者: Shimajiri, Takuya; Kawaguchi, Soki; Suzuki, Takanori; Ishigaki, Yusuke
• 署名单位: Hokkaido University; Hokkaido University; University of Tokyo
• 刊物名称: Nature
• ISSN/ISSBN: 0028-4683
• DOI: 10.1038/s41586-024-07965-1
• 发表日期: 2024-10-10
• 关键词: spin-resonance; trivalent carbon; cation radicals; ethane; cope; hexamethyldisilane; cleavage; spectrum; anions; c2h6+

摘要

Covalent bonds share electron pairs between two atoms and make up the skeletons of most organic compounds in single, double and triple bonds. In contrast, examples of one-electron bonds remain scarce, most probably due to their intrinsic weakness1-4. Although several pioneering studies have reported one-electron bonds between heteroatoms, direct evidence for one-electron bonds between carbon atoms remains elusive. Here we report the isolation of a compound with a one-electron sigma-bond between carbon atoms by means of the one-electron oxidation of a hydrocarbon with an elongated C-C single bond5,6. The presence of the C center dot C one-electron sigma-bond (2.921(3) & Aring; at 100 K) was confirmed experimentally by single-crystal X-ray diffraction analysis and Raman spectroscopy, and theoretically by density functional theory calculations. The results of this paper unequivocally demonstrate the existence of a C center dot C one-electron sigma-bond, which was postulated nearly a century ago7, and can thus be expected to pave the way for further development in different areas of chemistry by probing the boundary between bonded and non-bonded states. The one-electron oxidation of a hydrocarbon with an elongated C-C single bond provides direct evidence for a one-electron sigma-bond between carbon atoms.