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

One-electron oxidation of the stibines Aryl3 Sb (1, Aryl=2,6-i Pr2 -4-OMe-C6 H2 ; 2, Aryl=2,4,6-i Pr3 -C6 H2 ) with AgSbF6 and NaBArylF 4 (ArylF =3,5-(CF3 )2 C6 H3 ) afforded the first structurally characterized examples of antimony-centered radical cations 1.+ [BArylF 4 ]- and 2.+ [BArylF 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.+ [BArylF 4 ]- and p-benzoquinone afforded a dinuclear antimony dication salt 32+ [BArylF 4 ]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.