Lanthanide compounds with fluorinated OC6F5 ligands: Homo- and heterovalent complexes of Eu(II) and Eu(III)

Article abstract of DOI:10.1021/ic062395e

The fluorinated phenoxide OC₆F₅ forms the stable Eu(II) and Eu(III) derivatives (DME)₂Eu(μ-OC₆F ₅)₃Eu(μ-OC₆F₅) ₃-Eu(DME)₂ and (DME)₂Eu(OC₆F ₅)₃, as well as the heterovalent product (DME) ₂Eu(μ-OC₆F₅)₃Eu(DME)(OC ₆F₅)₂, in redox reactions of Eu with HOC ₆F₅ or in proton-transfer reactions of HOC ₆F₅ with Eu(SPh)₂. The divalent complex crystallizes as a trimer with three bridging phenoxides bridging each pair of metals, with the terminal metals coordinating DME and the central metal ion encapsulated totally by O(C₆F₅) and dative fluoride interactions. The trivalent compound is monomeric with terminal phenoxide ligands and no Eu-F interactions. The heterovalent compound has clearly localized metal valence states and coordination features that mimic the homovalent species with the terminal OC₆F₅ bound to the Eu(III) ion, three bridging OR ligands spanning the Eu(II) and Eu(III) ions, and dative Eu(II)-F bonds. At elevated temperatures, these compounds decompose to give a mixture of solid-state fluoride phases.