A Room‐Temperature Stable Distonic Radical Cation. (19th October 2020)

• Record Type: Journal Article
• Authors: Chen, Xiaodan; Liu, Liu Leo; Liu, Shihua; Grützmacher, Hansjörg; Li, Zhongshu
• Is Part Of: Angewandte Chemie. Volume 132:Number 52(2020)
• Page Start: 24038
• Page End: 24043
• Publication Date: 2020-10-19
• Subjects: carbenes -- dicarbondiphosphide -- distonic radical cations -- phosphorus -- radicals; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202011677
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Distonic radical cations (DRCs) with spatially separated charge and radical sites have, so far, largely been observed by gas‐phase mass spectrometry and/or matrix isolation spectroscopy work. Herein, we disclose the isolation of a crystalline dicarbondiphosphide‐based β‐distonic radical cation salt 3 .+ (BARF) (BARF=[B(3, 5‐(CF3 )2 C6 H3 )4 )] − ) stable at room temperature and formed by a one‐electron‐oxidation‐induced intramolecular skeletal rearrangement reaction. Such a species has been validated by electron paramagnetic resonance (EPR) spectroscopy, single‐crystal X‐ray diffraction, UV/Vis spectroscopy and density functional theory (DFT) calculations. Compound 3 .+ (BARF) exhibits a large majority of spin density at a two‐coordinate phosphorus atom (0.74 a.u.) and a cationic charge located predominantly at the four‐coordinate phosphorus atom (1.53 a.u.), which are separated by one carbon atom. This species represents an isolable entity of a phosphorus radical cation that is the closest to a genuine phosphorus DRC to date. Abstract : A crystalline dicarbondiphosphide‐based β‐distonic radical cation salt is isolated. The radical and charge sites are localized on diverse phosphorus atoms of the C2 P2 ring and separated by one carbon atom. This species is best viewed as a phosphorus distonic radical cation that is isolable and stable at room temperature.