Redox mediated dimerisation of a cyclo-As8 complex

Abstract

Reduction as well as oxidation of the cyclo-As₈ complex [{Cp′′Ta}₂(μ,η^2:2:2:2:1:1-As₈)] (A, Cp′′ = 1,3-^tBu₂C₅H₃) are demonstrated to afford controlled dimerisation to unprecedented As₁₆ species. The dication [{Cp′′Ta}₄(μ₄,η^{2:2:2:2:2:2:2:2:1:1:1:1}-As₁₆)]²⁺ slowly disproportionates in solution, yielding the largest polyarsenide species in a molecular complex known to date.