Syntheses, structures and theoretical calculations of stable triarylarsine radical cations

The first stable triarylarsine radical cation salts 1˙⁺[BAr^F₄]^- and 2˙⁺[BAr^F₄]^- were afforded by one-electron oxidation of triarylarsines Trip₃As (1, Trip = 2,4,6-iPr₃C₆H₂) and Dipp₃As (2, Dipp = 2,6-iPr₂C₆H₃) with AgSbF₆ and NaBAr^F₄ (Ar^F = 3,5-(CF₃)₂C₆H₃), respectively. Their molecular and electronic structures were investigated by single-crystal X-ray diffraction, electron paramagnetic resonance (EPR) and UV-vis absorption spectroscopy, in conjunction with density functional theory (DFT) calculations. The EPR and computational results demonstrate that the spin density of 1˙⁺ and 2˙⁺ is mainly distributed on the As nuclei.