One‐ and Two‐Electron Transfer Oxidation of 1,4‐Disilabenzene with Formation of Stable Radical Cations and Dications

• Published in: Chemistry : a European journal Vol. 28; no. 5; pp. e202103715 - n/a
• Main Authors: Chen, Yilin, Chen, Zhikang, Jiang, Liuyin, Li, Jiancheng, Zhao, Yiling, Zhu, Hongping, Roesky, Herbert W.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 24.01.2022; Wiley Subscription Services, Inc; John Wiley and Sons Inc
• Subjects: 1,4-disilabenzene; Absorption spectroscopy; Anions; Cations; Chemistry; Chemistry, Multidisciplinary; Crystallography; dication; Electron transfer; Magnetic resonance spectroscopy; NMR; NMR spectroscopy; Nuclear magnetic resonance; organometallic oxidant; Oxidants; Oxidation; Oxidizing agents; Physical Sciences; radical cation; Science & Technology; Spectroscopic analysis; Spectrum analysis; TRIS(PENTAFLUOROPHENYL)BORANE; organometallic oxidant; REACTIVITY; FRUSTRATED LEWIS PAIRS; PI-BONDS; radical cation; VALENCE ISOMERIZATION; HYDROGEN; electron transfer; 1,4-disilabenzene; dication; ARYL RADICALS; GENERATION; SUBSTITUTED SILYL RADICALS; ISOLABLE SILYL
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202103715

Electron‐transferable oxidants such as B(C6F5)3/nBuLi, B(C6F5)3/LiB(C6F5)4, B(C6F5)3/LiHBEt3, Al(C6F5)3/(o‐RC6H4)AlH2 (R=N(CMe2CH2)2CH2), B(C6F5)3/AlEt3, Al(C6F5)3, Al(C6F5)3/nBuLi, Al(C6F5)3/AlMe3, (CuC6F5)4, and Ag2SO4, respectively were employed for reactions with (L)2Si2C4(SiMe3)2(C2SiMe3)2 (L=PhC(NtBu)2, 1). The stable radical cation [1]+. was formed and paired with the anions [nBuB(C6F5)3]− (in 2), [B(C6F5)4]− (in 3), [HB(C6F5)3]− (in 4), [EtB(C6F5)3]− (in 5), {[(C6F5)3Al]2(μ‐F)]− (in 6), [nBuAl(C6F5)3]− (in 7), and [Cu(C6F5)2]− (in 8), respectively. The stable dication [1]2+ was also generated with the anions [EtB(C6F5)3]− (9) and [MeAl(C6F5)3]− (10), respectively. In addition, the neutral compound [(L)2Si2C4(SiMe3)2(C2SiMe3)2][μ‐O2S(O)2] (11) was obtained. Compounds 2–11 are characterized by UV‐vis absorption spectroscopy, X‐ray crystallography, and elemental analysis. Compounds 2–8 are analyzed by EPR spectroscopy and compounds 9–11 by NMR spectroscopy. The structure features are discussed on the central Si2C4‐rings of 1, [1]+., [1]2+, and 11, respectively. Compounds [1]+.[R]− and [1]2+ ⋅ 2[R]− have been prepared from the respective one‐ and two‐electron transfer reactions of 1,4‐disilabenzene (L)2Si2C4(SiMe3)2(C2SiMe3)2 (1) by using the transferable organometallic oxidants and characterization by X‐ray crystallography.