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