Two tetrathiafulvalene salts of a new thiophene-functionalised ferracarborane: electrical conductivity as a function of crystal composition

Abstract

Two tetrathiafulvalenium (TTF) salts of the new sandwich complex commo-[3,3′-Fe{1-(thiophene-2-yl)-1,2-C₂B₉H₁₀}₂]^–, [TTF][Fe(C₂B₉H₁₀C₄H₃S)₂] and [TTF]₅[Fe(C₂B₉H₁₀C₄H₃S)₂]₂, are synthesized; while the 1 : 1 salt is an insulator, the 5 : 2 salt is a semiconductor featuring a conducting superlattice associated with a sublattice that shows ferromagnetic interactions between the ferracarborane complexes; single crystal X-ray studies of the 5 : 2 salt indicate that the electrical conductivity originates from a unique mixed-valence TTF network.