title: An isolable NHC-stabilized silylene radical cation: synthesis and structural characterization.
abstract: The silyl-substituted silylene-NHC complex bis(tri-tert-butylsilyl)silylene-(1,3,4,5-tetramethylimidazol-2-ylidene) [((t)Bu(3)Si)(2)Si:←NHC(Me), 2] was synthesized and isolated as air- and moisture-sensitive orange crystals by reductive debromination of the dibromosilane ((t)Bu(3)Si)(2)SiBr(2) (1) with 2.0 equiv of KC(8) in the presence of NHC(Me). In addition, the silylene-NHC complex 2 cleanly underwent one-electron oxidation with 1.0 equiv of Ph(3)C(+)·Ar(4)B(-) (Ar(4)B(-) = tetrakis[4-(tert-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl]borate) in benzene to afford the NHC-stabilized silylene radical cation [((t)Bu(3)Si)(2)Si←NHC(Me)](•+)·Ar(4)B(-) (3). The radical cation 3 was isolated as air- and moisture-sensitive yellow crystals and structurally characterized by X-ray crystallography and electron paramagnetic resonance spectroscopy, which showed that 3 has a planar structure with a π-radical nature.
authors.affiliation: Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ichinohe
authors.forename: Akira
authors.initials: A
authors.lastname: Sekiguchi