Anionic Iron Complexes with a Bond between an Ate-Type Pentacoordinated Germanium and an Iron Atom

Kano, Naokazu; Yoshinari, N; Shibata, Yusuke; Miyachi, Mariko; Kawashima, Takayuki; Enomoto, Masaya; Okazawa, Atsushi; Kojima, Naoya; Guo, Jing‐Dong; Nagase, Shigeru

doi:10.1021/om300915y

Cited by 23 publications

(15 citation statements)

References 46 publications

(29 reference statements)

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“…In 12 , the Pt–Si distance (2.391 Å) is almost the same as the sum of the covalent bond radii of Pt and Si (2.39 Å),34 indicating that this hypervalent Pt–Si bond is not weak. Transition‐metal complexes bearing a similar short M–ER 4 (E = Si or Ge) bond were reported for Fe complexes by Kano and co‐workers35 and for Co complexes by Deng and co‐workers 36. The concerted oxidative addition of the Si–F σ bond starting from 12 is difficult, as previously reported;37 both trans ‐ and cis ‐oxidative additions leading to the formation of 13 and 14 , respectively, require very large activation energies, as shown in Figure B,C.…”

Section: Participation Of the Lewis Acid In Stoichiometric σ‐Bond Actsupporting

confidence: 70%

Cooperative Catalysis of Combined Systems of Transition‐Metal Complexes with Lewis Acids: Theoretical Understanding

Guan

Zeng

Kameo

et al. 2016

The Chemical Record

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The combination of transition-metal complexes and Lewis acids has been recently applied to several catalytic reactions, in which the Lewis acid plays a crucial role as a non-innocent additive to accelerate the reaction. In this review article, the reasons for the acceleration by the Lewis acid are discussed based on our recent theoretical studies. In the H-H σ-bond activation of a dihydrogen molecule by a nickel(0)-borane complex, the empty p orbital of the borane moiety interacts with the H-H σ bonding MO to form charge transfer (CT) from the dihydrogen molecule to the borane moiety to accelerate the reaction. In the B-F σ-bond activation of BF by a platinum(0)-bisphosphine complex, the second BF molecule interacts with the F atom that is dissociating from the B atom to stabilize the transition state and product by the CT from the F atom to the second BF . In this reaction, the substrate BF plays a crucial role as the Lewis acid to accelerate the activation of the B-F σ bond. In the nickel-catalyzed decyanative coupling of arylcarboxybenzonitriles with acetylenes, two molecules of the aluminum Lewis acid interact with the cyano N atom and the carbonyl O atom of the substrate to stabilize the transition state and intermediate. In the nickel-catalyzed alkylation of aromatic amides with alkenes, the Lewis acid enhances the para regioselectivity of alkylation by interacting with the carbonyl O atom. In the nickel-catalyzed carboxylation of sp carbon and sp carbon atoms with carbon dioxide, not the σ-bond activation but the insertion reaction of carbon dioxide into the metal-carbon bond is accelerated by the Lewis acid by interacting with the O atom of carbon dioxide, because the CT from the metal-carbon bond to carbon dioxide is enhanced by the interaction. This theoretical knowledge suggests that the combination of transition-metal complex and Lewis acid can broaden the application range of transition-metal complex as catalyst.

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Section: Participation Of the Lewis Acid In Stoichiometric σ‐Bond Actsupporting

confidence: 70%

Cooperative Catalysis of Combined Systems of Transition‐Metal Complexes with Lewis Acids: Theoretical Understanding

Guan

Zeng

Kameo

et al. 2016

The Chemical Record

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“…Examples of previously characterized M-Fp complexes also are included in Table 1. The Mössbauer parameters for these complexes that feature either Ge-Fp 28 or Fe-Fp 29 bonds are within the range observed for typical Fp-X complexes (entries 8-10). In this context, the Cu-Fe complexes (IPr)Cu-Fp and (IMes) Cu-Fp, as well as the Zn-Fe complex (IPr)(Cl)Zn-Fp, were found to have unusual Mössbauer parameters (entries 11-13): the isomer shifts are large (0.30-0.42 mm s −1 ) and the quadrupole splittings are small (0.72-0.77 mm s −1 ) compared to previously characterized Fp-containing complexes.…”

Section: Mössbauer Spectroscopysupporting

confidence: 66%

Experimental determination of redox cooperativity and electronic structures in catalytically active Cu–Fe and Zn–Fe heterobimetallic complexes

et al. 2014

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Complexes of the type (NHC)M-Fp (NHC = N-heterocyclic carbene, M = Cu or ZnCl, Fp = FeCp(CO)2) have been used recently as replacements for noble metal C-H functionalization catalysts and for small molecule activation studies. The promising reactivity of these systems has been linked to the use of the late metal electrophiles Cu and Zn in place of early metal electrophiles, and also to the ability of the M-Fe pairs to cooperate during catalytically relevant multielectron redox processes such as bimetallic oxidative addition and bimetallic reductive elimination. Using Mössbauer spectroscopy and metal K-edge XANES analysis, a detailed electronic structure description of these complexes is presented. One unusual feature of the late-metal M-Fp interactions is the presence of significant M → Fe π-backdonation in addition to Fe → M σ-donation; this π-backdonation is absent in early metal analogues and is apparent from analysis of Mössbauer data and Fe K-edge data. Multi-edge XANES analysis of C-I bimetallic oxidative addition at a Cu-Fe reaction center reveals little change in metal effective nuclear charges during the two-electron redox process. IR spectroscopy indicates that the supporting carbonyl ligands participate to a large extent in the redox process.

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“…The values obtained for 1 occupy a somewhat unique niche for Cp(CO) 2 Fe−X complexes. The δ value of 1 is larger than those of formally Fe 2+ Cp(CO) 2 Fe−X species in which X is not a π‐donor ligand (X=CN/CH 3 : δ =0.069/0.069 mm s −1 ; Δ E Q =1.899/1.746 mm s −1 at 78 K), as well as in formally Fe 0 Cp(CO) 2 Fe−X species (X=LGe 4+ (at 78 K)/LFe 2+ (at 190 K): δ =0.084/0.080 mm s −1 ; Δ E Q =1.74/1.73 mm s −1 ) ,. However, the δ value measured for 1 is lower than in formally Fe 2+ Cp(CO) 2 Fe−X complexes where X is a σ‐ and a π‐donor ligand (X=NCS/I: ( δ =0.202/0.215 mm s −1 ; Δ E Q =1.878/1.840 mm s −1 at 78 K) .…”

Section: Methodsmentioning

confidence: 92%

Structure and Magnetization Dynamics of Dy−Fe and Dy−Ru Bonded Complexes

et al. 2018

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We present an investigation of isostructural complexes that feature unsupported direct bonds between a formally trivalent lanthanide ion (Dy3+) and either a first‐row (Fe) or a second‐row (Ru) transition metal (TM) ion. The sterically rigid, yet not too bulky ligand PyCp22− (PyCp22−=[2,6‐(CH2C5H3)2C5H3N]2−) facilitates the isolation and characterization of PyCp2Dy−FeCp(CO)2 (1; d(Dy–Fe)=2.884(2) Å) and PyCp2Dy−RuCp(CO)2 (2; d(Dy–Ru)=2.9508(5) Å). Computational and spectroscopic studies suggest strong TM→Dy bonding interactions. Both complexes exhibit field‐induced slow magnetic relaxation with effectively identical energy barriers to magnetization reversal. However, in going from Dy−Fe to Dy−Ru bonding, we observed faster magnetic relaxation at a given temperature and larger direct and Raman coefficients, which could be due to differences in the bonding and/or spin–phonon coupling contributions to magnetic relaxation.

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Anionic Iron Complexes with a Bond between an Ate-Type Pentacoordinated Germanium and an Iron Atom

Cited by 23 publications

References 46 publications

Cooperative Catalysis of Combined Systems of Transition‐Metal Complexes with Lewis Acids: Theoretical Understanding

Cooperative Catalysis of Combined Systems of Transition‐Metal Complexes with Lewis Acids: Theoretical Understanding

Experimental determination of redox cooperativity and electronic structures in catalytically active Cu–Fe and Zn–Fe heterobimetallic complexes

Structure and Magnetization Dynamics of Dy−Fe and Dy−Ru Bonded Complexes

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