Elusive Antimony‐Centered Radical Cations: Isolation, Characterization, Crystal Structures, and Reactivity Studies

One‐electron oxidation of the stibines Aryl 3 Sb ( 1 , Aryl=2,6‐ i Pr 2 ‐4‐OMe‐C 6 H 2 ; 2 , Aryl=2,4,6‐ i Pr 3 ‐C 6 H 2 ) with AgSbF 6 and NaBAryl F 4 (Aryl F =3,5‐(CF 3 ) 2 C 6 H 3 ) afforded the first structurally characterized examples of antimony‐centered radical cations 1 .+ [BAryl F 4 ] − and 2 .+ [BAryl F 4 ] − . Their molecular and electronic structures were investigated by single‐crystal X‐ray diffraction, electron paramagnetic resonance spectroscopy (EPR) and UV/Vis absorption spectroscopy, in conjunction with theoretical calculations. Moreover, their reactivity was investigated. The reaction of 2 .+ [BAryl F 4 ] − and p ‐benzoquinone afforded a dinuclear antimony dication salt 3 2+ [BAryl F 4 ] 2 − , which was characterized by NMR spectroscopy and X‐ray diffraction analysis. The formation of the dication 3 2+ further confirms that the isolated stibine radical cations are antimony‐centered.