Diferrocenylmercury‐Bridged Diphosphine: A Chiral, Ambiphilic, and Redox‐Active Bidentate Ligand

A diphosphine chelate ligand with a wide and flexible bite angle, a unique stereochemical environment, and redox‐active and ambiphilic character is reported. Initially generated as its HgCl 2 complex by reaction of 1,2‐fc(PPh 2 )(SnMe 3 ) (fc=ferrocenediyl) with HgCl 2 in acetone, treatment with [ n ‐Bu 4 N]CN readily liberates the free chiral bidentate ligand. An intermolecular ClHg−Cl→Hgfc 2 (2.9929(13) Å) interaction that is unprecedented in ambiphilic ligand chemistry is seen in the solid structure of Hg(fcPPh 2 ) 2 ⋅HgCl 2 where the bridging mercury atom acts as a σ‐acceptor. Furthermore, a bis‐[Rh(COD)Cl] complex is introduced, which displays relatively short Rh⋅⋅⋅Hg contacts of 3.4765(5) and 3.4013(1) Å. Wiberg indices of 0.12 are determined for these Rh⋅⋅⋅Hg interactions and an AIM analysis reveals bond paths with an electron density ρ ( r ) of 1.2×10 −2 and 1.4×10 −2  e/a 0 3 at the bond critical points.