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The electron-transfer chain catalysed chelation of the dithiocarbamate ligand in Fp*(σ-dtc)(1)[Fp*= Fe(η5-C5Me5)(CO)2; dtc = SC(S)NMe2] can be initiated by cathodic reduction or by naphthyl-sodium (as well as by ferricinium salts) to give [Fe(C5Me5)(CO)(n;2-dtc)](2) and CO; the choice of the reducing agent is crucial because of counter-ion effects in the propagation cycle, and the oxidative and reductive modes of initiation are compared.

The blue 19e complex [FeIII(C5Me5)(η2-S2CNMe2)2]1, generated by addition of NaS2CNMe2 to the 17e complex [FeIII(C5Me5)(η2-S2CNMe2)(MeCN)]PF6 in MeCN at –45 °C or by monoelectronic reduction of the 18e cation 1+ using the 19e complex [FeI(C5H5)(C6Me6)] in THF at –80 °C gives the purple 17e form [FeIII(C5Me5)(η2-S2CNMe2)-{η1-SC(S)NMe2}]2 in solution and in the solid state; both the 17e and 19e forms are characterized by their specific ESR and Mossbauer spectra and by cyclic voltammetry.

The C–O bond of Fe(η5-C5H5)+ complexes of aryl ethers is cleaved smoothly by reaction of ButOK in THF or KOH in DME, yielding π-phenate complexes; transetherification can also be achieved in situ at room temperature.

The pKa values and bond dissociation energies of 19-electron complexes have been determined for the first time, supporting the concept of proton and hydrogen atom reservoirs for late transition-metal sandwich complexes.

The reaction between the 19-electron complex [FeI(C5H5)(C6Me6)] 1 and C60 in toluene gives the paramagnetic salts (1+)C60-, (1+)C-2(60)2- and (1+)C-3(60)3- depending on the stoichiometry of the reactants

Several new polyaromatic iron complexes have been synthesized with C5H5 or C5Me5 ligands and the synthesis of others is much improved using molten components; cyclic voltammetry shows a considerable stabilization of the FeI state by permethylation of the C5H5 ligand, and a wide range of spin distribution on the polyaromatic ligand: biphenyl ∼ triphenylene ⩽ naphthalene < phenanthrene < pyrene < perylene ⩽ corronene, is found for the C5H5 complexes only.

The complexes [(η5-C5H5)Fe(CO)2{η1-SC(S)NR2}](R = Me or Et) react with KCN in methanol to give the five-membered-metallocycles K[(η5-C5H5)[graphic omitted]N)}](2) which can be acylated by PhCOCl giving [(η5–C5H5)[graphic omitted]NCOPh)}](3) which had been characterized by X-ray diffraction for the complex with R = Et.

The new bimetallic complex (cpFe)(cp–cp)(FeC6Me6)+PF6–, (cp = C5H5)(2), synthesized from biferrocene and C6Me6, shows four oxidation states (FeIIIFeII)2+, (FeIIFeII)+, FeIIFeI, and (FeIIFe0)– reversibly connected by cyclic voltammetry; the first three are stable and can be isolated and Mossbauer spectroscopy was used to investigate the electronic structure of the localized mixed valence FeIIFeI.

The low temperature 13C n.m.r. spectrum of (C6Et6)Cr(CO)2CS shows the molecule to have Cs symmetry as it does in the solid state; this result provides the first clear evidence of cessation of tripodal rotation in a neutral half-sandwich compound of Cr.

Na[(η5-C5Me5)Fe(CO)2](1), a precursor of (η5C5Me5)Fe(CO)2(CH2OMe)(2), is conveniently obtained by Na-Hg reduction of [(η5-C5Me5)Fe(CO)2]2 overnight (20 °C), complex (2) yielding [(η5-C5Me5)Fe(CO)2(CH2PPh3)]BF4(3) upon acid treatment in the presence of PPh3 and converting styrene quantitatively into phenylcyclopropane upon reaction with Me3SiOSO2CF3 giving (η5-C5Me5)Fe(CO)2(OSO2CF3)(4); photolysis of (2)+ PPh3 produces (η5-C5Me5)Fe(CO)-(PPh3)(CH2OMe)(5) which upon acid treatment affords the methylene complex [(η5-C5Me5)Fe(CO)(PPh3)(CH2)]+(6).

A low temperature spectroscopic study of the facile arene exchange by phosphines and phosphites in the air-sensitive 19 electron complexes [FeICp(η6-arene)], (Cp = cyclopentadienyl, η5-C5H5), shows an associative pathway in the rate limiting step, which suggests a fast pre-equilibrium generating a 17 electron species.

Activation of a carbonyl group in cationic organometallic substrates such as the acylcyclopentadienylareneiron complexes(I), (V), and (VII) renders its electrochemical reduction easy and stereospecific, providing a route to the primary and secondary cationic alcohols (II) and (VI) or to the dinuclear dicationic pinacols (III).

The reaction between [Fe(C5Me5)(CO)2Br] and C6Et6 in the presence of AlCl3 does not give [Fe(C5Me5)(C6Et6)]+ but, in the prsence of protic impurities, [Fe(C5Me5)(C6Et5H)]+ is the only cation formed; the X-ray crystal structure of its PF6– salt shows that all Et substituents are distal and a σ intermediate is proposed for the complexation.

The thermally unstable complex FeI(cp)(C6Me5NH2), (cp =η5C5H5) reacts with 1/4 mol of O2 at –10 ° C in toluene to give FeII(cp)(η5C6Me5NH), the N–H being activated by O2, consistent with an electron transfer mechanism O2→ O2˙–; the latter complex reacts with CO2(20 °C, 1 atm) providing Fe+(cp)(η6-C6Me5NHCO2–).

The 19 electron complexes [FeI(cp)(C6R6)], R = H (1) or Me (2), cp =η5-C5H5, reduce CO2 in tetrahydrofuran to give [FeII(cp)(C6R6)]+, ½ CO32–, and ½ CO; in the presence of PMe3 and Na+PF6–, reduction of CO2 yields Na2CO3, [FeII(cp)(PMe3)3]+[PF6]–(3+), and [FeII(cp)(PMe3)2CO]+[PF6]–(4+) resulting from the reactions of the very electron-rich 19 electron species [FeI(cp)(PMe3)3](3).

Terminal alkynes (RC2H; R = Ph, Bun) are instantaneously polymerized at 20 °C by 1% of W(CO)3(NCMe)3(1) and 0.01% of [Fe(cp)2]+PF6–(2) in a system which couples electrocatalysis (electron transfer chain) with organometallic catalysis (cp =η5-cyclopentadienyl).