Synthesis and characterisation of dirhodium(II) tetraacetates bearing axial ferrocene ligands

Symmetrical dirhodium(II) tetracarboxylate complexes bearing ferrocene-based supporting ligands in the axial positions, viz. [Rh-2(CH3CO2)(4)L-2] (1-3), where L = (diphenylphosphino)ferrocene (1), cyanoferrocene (2), and isocyanoferrocene (3), were prepared from [Rh-2(CH3CO2)(4)] and the respective ferrocene derivative in ethanol. These complexes were structurally characterised by spectroscopic methods, single-crystal X-ray diffraction analysis and cyclic voltammetry. Our results showed that while compounds 1 and 3 are stable in both solid state and solution (complex 1 is very poorly soluble), the nitrile complex 2 easily decomposes through the loss of the isocyanide ligands. (C) 2021 Elsevier B.V. All rights reserved.