Characterization of an Iron–Ruthenium Interaction in a Ferrocene Diamide Complex

Abstract

Reaction of [fc(NH2)2]RuCl2(PPh3)2 (fc = 1,1'-ferrocenylene) with 2 equiv of KO(t)Bu led to the formation of a diamido ruthenium complex, [fc(NH)2]Ru(PPh3)2, whose solid-state molecular structure revealed a short Fe-Ru distance. A metal-to-metal charge transfer band was observed in the electronic absorption spectrum of [fc(NH)2]Ru(PPh3)2. The Fe-Ru interaction was characterized by resonance Raman spectroscopy for the first time and also by (1)H NMR, UV-vis, NIR, Mössbauer spectroscopy, and X-ray crystallography. Density functional theory (DFT) calculations including natural bond order analysis, Bader's atom in molecules method, and time-dependent DFT (TDDFT) provided further support that the iron-ruthenium bond is a weak donor-acceptor interaction with iron acting as the Lewis base.

Rare Earth Arene-Bridged Complexes Obtained by Reduction of Organometallic Precursors

“…In the area of early transition metals, J. . Recently, our group also reported a dative Fe-Ru interaction in [Fe( 5 -C5H4NH)2]Ru(PPh3)2 and characterized it by spectroscopic methods and DFT calculations (Green et al, 2013). Besides the weak Fe-M interaction, ferrocene-based ligands inherit the redox-active nature of ferrocene.…”

Yttrium-Alkyl Complexes Supported by a Ferrocene-Based Phosphinimine Ligand

“…[26][27] In those cases, the ligand framework was a ferrocenediamide that could support a weak donor-acceptor interaction between the metal in the ligand. 18,[28][29][30] In another case, a pyridine-diamide ligand was prepared in order to probe the significance of this interaction; the resulting yttrium and lutetium complexes showed analogous reactivity toward aromatic N-heterocycles, but the reactions were less straightforward than in the case of complexes supported by ferrocene diamide ligands. 31 Other groups have prepared rare-earth metal complexes supported by pyridine-diamide ligands for the polymerization of ethylene and methyl methacrylate.…”

Beyond Common Metal–Metal Bonds, κ3‐Bis(donor)ferrocenyl→Transition‐Metal Interactions

“…Switching from acceptor PPh 3 to the better donor PMe 2 Ph resulted in a small contraction of the intermetallic distance ( d Fe−Ru =2.77 Å) (Scheme ). The Fe→Ru bond could be disrupted only by treatment of [ 22 ] with excess PMe 2 Ph which yielded [Ru(PMe 2 Ph) 3 (Fe(C 5 H 4 NH) 2 )] ([ 23 ]) (Scheme ) …”