Dialkyl dichalcogen cations

One electron oxidation of dialkyl diselenides and ditellurides is achieved with NO+CF3SO3−. According to ab initio calculations the radical cations have a trans stucture. In the solid state they dimerize to rectangular units [R–Te]42+ and [R–Se]42+. The long Se⋯Se and Te⋯Te bond is obviously due to a π*–π* interaction.