Diaryldichalcogenide radical cations

Abstract

One-electron oxidation of two series of diaryldichalcogenides (C₆F₅E)₂ (<b>13a-c</b>) and (2,6-Mes₂C₆H₃E)₂ (<b>16a-c</b>) was studied (E = S, Se, Te). The reaction of <b>13a</b> and <b>13b</b> with AsF₅ and SbF₅ gave rise to the formation of thermally unstable radical cations [(C₆F₅S)₂]˙⁺ (<b>14a</b>) and [(C₆F₅Se)₂]˙⁺ (<b>14b</b>) that were isolated as [Sb₂F₁₁]^- and [As₂F₁₁]^- salts, respectively. The reaction of <b>13c</b> with AsF₅ afforded only the product of a Te-C bond cleavage, namely the previously known dication [Te₄]²⁺ that was isolated as [AsF₆]^- salt. The reaction of (2,6-Mes₂C₆H₃E)₂ (<b>16a-c</b>) with [NO][SbF₆] provided the corresponding radical cations [(2,6-Mes₂C₆H₃E)₂]˙⁺ (<b>17a-c</b>; E = S, Se, Te) in the form of thermally stable [SbF₆]^- salts in nearly quantitative yields. The electronic and structural properties of these radical cations were probed by X-ray diffraction analysis, EPR spectroscopy, and density functional theory calculations and other methods.