Sb⋯S and S⋯S interactions in the first neutral and oxidized diphenylstibino (Ph2Sb–) derivatives of the redox active tetrathiafulvalene (TTF) core

Abstract

The preparation of the monostibines o-Me₂TTF–SbPh₂ (1) and Me₃TTF–SbPh₂ (2), the ortho distibine o-Me₂TTF(SbPh₂)₂ (3) and the tetrastibine TTF(SbPh₂)₄ (4) is described together with their electrochemical properties and the X-ray crystal structures of the neutral 1 and 3. In the former, one intermolecular Sb⋯S contact completes the co-ordination sphere of the antimony atom while in 3 the TTF moieties stack on top of each other with no evidence for Sb⋯S interactions. Electrocrystallisation of 2 in the presence of [n-Bu₄N]₂[Mo₆O₁₉] affords a 2 ∶ 1 salt, [2]₂[Mo₆O₁₉] where the 2⁺˙ cation radical species are associated into diamagnetic [2]₂²⁺dyads through a strong HOMO⋯HOMO overlap interaction, separated from each other by the [Mo₆O₁₉]²⁻ counter ions.