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

One‐electron oxidation of the stibines Aryl3Sb (1, Aryl=2,6‐iPr2‐4‐OMe‐C6H2; 2, Aryl=2,4,6‐iPr3‐C6H2) with AgSbF6 and NaBArylF4 (ArylF=3,5‐(CF3)2C6H3) afforded the first structurally characterized examples of antimony‐centered radical cations 1.+[BArylF4]− and 2.+[BArylF4]−. 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.+[BArylF4]− and p‐benzoquinone afforded a dinuclear antimony dication salt 32+[BArylF4]2−, which was characterized by NMR spectroscopy and X‐ray diffraction analysis. The formation of the dication 32+ further confirms that the isolated stibine radical cations are antimony‐centered.