Studies on 2–6-η5-cyclohexadienone-η5-cyclopentadienyliron and some related systems

Syntheses of the Complete Set of Isomerically Pure, Partially Fluorinated Cyclopentadienyl Ligands (C5F5-nHn) [n = 1−4] by Flash Vacuum Thermolysis of (η5-Oxocyclohexadienyl)ruthenium Complexes. Molecular Structures of [Ru(η5-C5Me5)(η5-C5-1,2-F2H3)] and [Ru(η5-C5Me5)(η5-C5H4F)]

“…Indeed, the hydrogen-bonding ability of the oxygen atom in analogous oxocyclohexadienyl ligands is well-established. X-ray crystallographic studies have demonstrated that complexes 18 and 19 show this hydrogen-bonding ability to phenol, , and NMR studies have also illustrated a 1:1 solution interaction between D 2 O and a series of oxocyclohexadienyliron complexes like 20 . The number of water molecules associated with 6 , 9 , 10 , and 11 , as indicated by microanalysis data, correlates inversely to υ C  O and also to the number and relative position of F substituents on the fluorooxocyclohexadienyl ligand.…”

Synthesis and Reactivity of Iron-Oxocyclohexadienyl Complexes toward Proton-Coupled Electron Transfer

“…Transition-metal complexes bearing oxocyclohexadienyl ligands have been reported for 40 years . Several groups reported the synthesis and structures of iron-sandwich complexes bearing oxocyclohexadienyl ligands. − Helling, Astruc, and co-workers reported that the parent iron complex [CpFe(η 5 -C 6 H 5 O)] was protonated on the oxygen atom to afford a cationic η 6 -phenol complex [CpFe(η 6 -C 6 H 5 OH)] + (Figure b). , Also, Astruc and co-workers found that [CpFe(η 5 -C 6 H 5 O)] was reduced in cyclic voltammetry (CV) . We have envisaged that simultaneous protonation and reduction of the iron-oxocyclohexadienyl complex would generate a hypothetical hydrogenated iron complex [CpFe(η 6 -C 6 H 5 OH)], which could have a weak O–H bond.…”