Cyanide as a versatile Lewis base ligand at a dinitrogen-binding iron(II) centre: mono- and heteronuclear adducts

The ligated cyanide in trans-[FeH(CN)(dppe)2] is activated towards aroylation, alkylation and addition of various transition metal Lewis acids, in particular [WCl4(PPh3)2], [ReOCl3(PPh3)2], [PdCl2(PPh3)2] and [PtCl(Ph)(PPh3)2], to give, in the former case, mononuclear isocyanide complexes and, in the latter case, heteronuclear adducts with bridging cyanide. Their syntheses and spectroscopic characterisation are presented, as well as results of the X-ray diffraction analyses of a trinuclear complex with the {FeCNWNCFe} unit and of the parent cyano trans-[FeH(CN)(dppe)2] complex. The cyanide bridge allows the electronic communication between the metal centres as indicated by a cyclic voltammetric study.