Redox-Structural Correlations in Metal Thioether Macrocyclic Complexes: The Stabilisation of Mononuclear Silver(II) and Gold(II)

The complexation of Ag(I) and Au(I) by tri-, tetra-, penta- and hexathia crown thioethers is described. The mismatch between metal ion and ligand co-ordination leads to complexes which often incorporate unusual stereochemical features and therefore show novel redox properties in solution. The stabilisation of mononuclear Ag(II) and Au(II) radical complexes has been investigated spectroelectrochemically using electronic and esr spectroscopy. In particular, the single crystal X-ray structures and redox interconversion of [Au([9]aneS3)2]+/2+/3+ are described.