Co-ordination chemistry of octamethyl-5,5′-di(2-pyridyl)ferrocene†

Abstract

The platinum complex [{PtCl₂(C₂H₄)}₂(dpf*) 1 [dpf* = octamethyl-5,5′-di(2-pyridyl)ferrocene] has been obtained by the reaction of dpf* with K[PtCl₃(C₂H₄)]. The reaction of dpf* with [Cu(NCCH₃)₄]⁺[BF₄]^– afforded the copper complexes [Cu(dpf*)]⁺ [BF₄]^–2 and [Cu(dpf*)]⁺[CuCl₂]^–3 as well as the ferrocenium salt [dpf*]⁺[BF₄]^–4, depending on the stoichiometry. The crystal structures of 1–4 have been determined by X-ray diffraction. The dpf* acts as a bridging ligand in the case of 1 and as a trans-chelating ligand in 2 and 3, which contain near-linear two-co-ordinate copper centres. Complex 3 shows a remarkably short, ligand-unsupported Cu^I· · ·Cu^I contact [281.0(2) pm]. A cyclovoltammetric study of 2 revealed an unprecedentedly high anodic shift of the half-wave potential of the ferrocene moiety upon co-ordination of Cu⁺ by dpf*.