Synthetic [NiFe] models with a fluxional CO ligand

Abstract

A [NiFe] complex [(dppe)Ni(pdt)FeCp*(CO)] was isolated and characterized as two isomers [1(CO)] and [1'(CO)]. Heating the solution of [1(CO)] allowed it to convert into [1'(CO)]. The one-electron oxidation of [1'(CO)] to [1'(CO)] induced fluxional CO movement providing [1(CO)]. Recovery of [1(CO)] was realized by the one-electron reduction of [1(CO)].

Synthetic Designs and Structural Investigations of Biomimetic Ni–Fe Thiolates

“…Indeed, treating a CH 2 Cl 2 solution of [Ni­(NS 3 )] − salts with [Cp*Fe­(CO)­(MeCN) 2 ]­BF 4 generated a new complex with a single ν CO band shifted to lower energy vs the cationic iron precursor (Figure S20). On the basis of the relative positions of CO and Cp* ligands, two stereoisomers are possible (Scheme ), as have been observed for other Ni­(μ-SR) 2 Fe­(CO)­Cp* complexes. , The positive-ESI-mass spectrum shows intense peaks corresponding to M + and [M-CO] + (Figure S21). The isotopic distributions for both peak envelopes match simulated spectra (Figures S22 and S23).…”

“…As summarized in Scheme 3, NiCl 2 (R,R-DIPAMP) was converted to Ni(pdt)(R,R-DIPAMP). 31 P and 1 H NMR spectra confirm the diamagnetic nature of the complex (Figures S36−S37 3. NiCl 2 (N-chelate) + Fe(pdt)(CO) 2 (diphosphine).…”

“…Ni(μ-SR) 2 Fe(CO)Cp* complexes. 30,31 The positive-ESI-mass spectrum shows intense peaks corresponding to M + and [M-CO] + (Figure S21). The isotopic distributions for both peak envelopes match simulated spectra (Figures S22 and S23).…”

“…The 31 P NMR spectrum of {H[(dppv)(CO)Fe(μ-pdt)] 2 Ni]}BF 4 consists of five peaks, which can be assigned to the three isomeric hydrides (Figure S64). The relative intensities of the 1 H and 31 Additional insight into the structures of and relationships between the isomeric hydrides was provided by low temperature NMR studies (Figure S65). Solutions prepared by dissolving crystals of {H[(dppv)(CO)Fe(μ-pdt)] 2 Ni]}BF 4 in CD 2 Cl 2 at −80 °C contain exclusively the isomer with a hydride signal at δ −4.9.…”

Bimetallic nickel–cobalt hydrides in H2 activation and catalytic proton reduction

“…Reflecting interest in utilization of earth abundant metals for controlling energy storage and release, functional modeling of hydrogenases continues to attract considerable attention. Compared to [FeFe]-H 2 ase mimics, modeling the active site of [NiFe]-hydrogenases has proven more challenging17–23 and very few of the models clarify the processing of H 2 24–28. Especially, the nickel–iron hydride models [Ni( ii )HFe( ii )] + remain rare although they are important in modeling research 29.…”