Electron in a cube: Synthesis and characterization of perfluorocubane as an electron acceptor

• Published in: Science (American Association for the Advancement of Science) Vol. 377; no. 6607; pp. 756 - 759
• Main Authors: Sugiyama, Masafumi, Akiyama, Midori, Yonezawa, Yuki, Komaguchi, Kenji, Higashi, Masahiro, Nozaki, Kyoko, Okazoe, Takashi
• Format: Journal Article
• Language: English
• Published: 12.08.2022
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.abq0516

Fluorinated analogs of polyhedral hydrocarbons have been predicted to localize an electron within their cages upon reduction. Here, we report the synthesis and characterization of perfluorocubane, a stable polyhedral fluorocarbon. The key to the successful synthesis was the efficient introduction of multiple fluorine atoms to cubane by liquid-phase reaction with fluorine gas. The solid-state structure of perfluorocubane was confirmed using x-ray crystallography, and its electron-accepting character was corroborated electrochemically and spectroscopically. The radical anion of perfluorocubane was examined by matrix-isolation electron spin resonance spectroscopy, which revealed that the unpaired electron accepted by perfluorocubane is located predominantly inside the cage. A fluorinated cube The synthesis of a cube-shaped hydrocarbon nearly 60 years ago was a major event in chemistry, both because of the compound’s beautiful, high symmetry and its distinctly unnatural bonding geometry. Sugiyama et al . have now synthesized and structurally characterized a cubane derivative in which the hydrogen atoms at each vertex are replaced by fluorines (see the Perspective by Krafft and Riess). Consistent with theoretical predictions, low-temperature electron spin resonance spectroscopy suggests that the molecule centrally internalizes an electron upon reduction. —JSY A perfluorinated carbon cube internalizes an electron upon reduction.