Chalcogenide radical cations R2E•+ (E = S, Se, Te) are commonly short-lived intermediates of fundamental interest. Sulfide radical cations in particular are associated in vivo with oxidative stress and neuropathological processes. Having succeeded in the preparation of meta-terphenyl-based dichalcogenide radical cations R2E2•+ (E = S, Se, Te), and a telluride analogue R2Te•+ in the past, we aimed to complete the series regarding sulfur and selenium. Here we report on the single-electron oxidation of diarylchalcogenides MSFluindPhE (E = S, Se, Te; MSFluind = dispirofluorene-9,3'-(1',1',7',7'-tetramethyl-s-hydrindacen-4'-yl)-5',9"-fluorene) using XeF2 in the presence of KB(C6F5)4, which afforded deeply coloured and isolable radical cation salts MSFluindPhEB(C6F5)4 (E = S, Se, Te). Structural and electronic properties were characterised by electron paramagnetic spectroscopy, cyclic voltammetry, optical absorption spectroscopy and single crystal X-ray diffraction (E = Se, Te), combined with extensive quantum mechanical computations.
Komorr et al. (Sat,) studied this question.