Iron‐Promoted CC Bond Formation in the Gas Phase

Troiani, Anna; Rosi, Marzio; Garzoli, Stefania; Salvitti, Chiara; Petris, Giulia de

doi:10.1002/ange.201506932

Cited by 4 publications

(2 citation statements)

References 49 publications

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“…In addition, because of the higher activity of the "naked" species, entirely unexpected reactions can be encountered, as for example the unprecedented extrusion of a carbon atom from a benzene ring by an [M] + −CH 2 complex 5,56 or the abstraction of methylene from CH 2 Cl 2 and its coupling with a cyclopentadienyl ligand by [FeC 5 H 5 ] + . 64 Clearly, since the seminal work on these elusive carbene species by E. O. Fischer and his school 65 and the visionary explanation of Y. Chauvin 2 to recognize their role in metathesis processes, 66 metal−carbene complexes now occupy a central, well-accepted position in chemistry, be that in solution or in the gas phase.…”

Section: ■ Concluding Remarksmentioning

confidence: 99%

Bond Activation by Metal–Carbene Complexes in the Gas Phase

Zhou

Schlangen

et al. 2016

Acc. Chem. Res.

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"Bare" metal-carbene complexes, when generated in the gas phase and exposed to thermal reactions under (near) single-collision conditions, exhibit rather unique reactivities in addition to the well-known metathesis and cyclopropanation processes. For example, at room temperature the unligated [AuCH2](+) complex brings about efficient C-C coupling with methane to produce C2Hx (x = 4, 6), and the couple [TaCH2](+)/CO2 gives rise to the generation of the acetic acid equivalent CH2═C═O. Entirely unprecedented is the thermal extrusion of a carbon atom from halobenzenes (X = F, Cl, Br, I) by [MCH2](+) (M = La, Hf, Ta, W, Re, Os) and its coupling with the methylene ligand to deliver C2H2 and [M(X)(C5H5)](+). Among the many noteworthy C-N bond-forming processes, the formation of CH3NH2 from [RhCH2](+)/NH3, the generation of CH2═NH2(+) from [MCH2](+)/NH3 (M = Pt, Au), and the production of [PtCH═NH2](+) from [PtCH2](+)/NH3 are of particular interest. The latter species are likely to be involved as intermediates in the platinum-mediated large-scale production of HCN from CH4/NH3 (the DEGUSSA process). In this context, a few examples are presented that point to the operation of co-operative effects even at a molecular level. For instance, in the coupling of CH4 with NH3 by the heteronuclear clusters [MPt](+) (M = coinage metal), platinum is crucial for the activation of methane, while the coinage metal M controls the branching ratio between the C-N bond-forming step and unwanted soot formation. For most of the gas-phase reactions described in this Account, detailed mechanistic insight has been derived from extensive computational work in conjunction with time-honored labeling and advanced mass-spectrometry-based experiments, and often a coherent description of the experimental findings has been achieved. As for some transition metals, in particular those from the third row, the metal-carbene complexes can be formed directly from methane, coupling of the so-generated [MCH2] species with an inert molecule such as CH4, CO2, or NH3 constitutes a route to activate and functionalize methane under ambient conditions. Clearly, while these gas-phase studies cannot be translated directly to formally related processes in solution or those that occur at a surface, they nevertheless provide a conceptual mechanistic understanding and permit researchers to probe directly the remarkable intrinsic features of these elusive molecules and, in a broader context, help to identify the active site of a catalyst, the so-called "aristocratic atoms".

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Section: ■ Concluding Remarksmentioning

confidence: 99%

Bond Activation by Metal–Carbene Complexes in the Gas Phase

Zhou

Schlangen

et al. 2016

Acc. Chem. Res.

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“…[25] Considering that gas-phase clusters can be taken as model systems to describe the molecular-level properties of catalytic reactions and surface processes, [26] the zinc or zinc oxide-NO x À (x = 2, 3) anions may be ascribed to simplified catalyst prototypes in which chemical properties, such as size, charge, and stoichiometry can be finely tuned and where the redox properties of the ligands can be investigated separately and with limited interferences from those of the zinc atom. Therefore, in light of our interest in the gas-phase chemistry of SO 2 , [27] the reactivity of selected zinc and zinc oxide species coordinated to nitrate and nitrite ligands, namely ZnO(NO 3 ) 2 À , Zn-(NO 3 ) 2 À and Zn(NO 2 )(NO 3 ) À , toward sulfur dioxide were investigated by a combined approach of ion-molecule reaction experiments and theoretical calculations. These anionic complexes were chosen as they differ by the formal oxidation state of the zinc atom.…”

Section: Introductionmentioning

confidence: 99%

Sulfur Dioxide Oxidation by Zinc and Zinc Oxide Nitrate/Nitrite Complexes in the Gas Phase: An Interplay between Redox‐Active Ligands and Metal

Salvitti

Bandeira

Pepi

et al. 2023

Chemistry A European J

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Different oxidative pathways of sulfur dioxide promoted by ZnO(NO 3 ) 2 À , Zn(NO 3 ) 2 À and Zn(NO 2 )(NO 3 ) À are revealed by a joint investigation by mass spectrometry and theoretical calculations. The reactions are triggered by [Zn 2 + -O À * ] + or by the low-valence Zn + through oxygen ion transfer or electron transfer to SO 2 , respectively. The NO x À ligands intervene in the oxidation only when sulfur dioxide is converted to SO 3 À or SO 2 À , leading to the formation of zinc sulfate and zinc sulfite coordinated to nitrate or nitrite anions. Kinetic analyses show that the reactions are fast and efficient, and theory discloses the elementary steps, namely oxygen ion transfer, oxygen atom transfer and electron transfer, occurring through similar energy landscapes for the three reactive anions.

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Identifizierung eines Zweifach‐Koordinierten Eisen(I)‐Oxalat‐Komplexes

et al. 2022

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Exotische Oxidationszustände der Metalle der ersten Übergangsreihe haben in letzter Zeit großes Interesse geweckt. Um die Oxidationsstufen einer Reihe von Eisenoxalat-Komplexen zu untersuchen, wurde eine wässrige Lösung von Eisen(III)-nitrat und Oxalsäure mittels Flüssigstrahl-Infrarot-Laser-Desorptions-und Elektrospray-Massenspektrometrie untersucht. Wir zeigen, dass Eisen nicht nur in seinen üblichen Oxidationsstufen + II und + III, sondern auch in der ungewöhnlichen Oxidationsstufe + I nachgewiesen werden kann, sowohl im positiven als auch im negativen Ionenmodus. Die Gasphasenschwingungsspektren der anionischen Eisenoxalat-Komplexe [Fe III (C 2 O 4 ) 2 ] À , [Fe II (C 2 O 4 )CO 2 ] À und [Fe I (C 2 O 4 )] À werden mit Hilfe von Infrarot-Photodissoziationsspektroskopie gemessen und ihre Strukturen durch Vergleich mit berechneten anharmonischen Schwingungsspektren auf der Grundlage der Störungstheorie zweiter Ordnung zugeordnet.

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Iron‐Promoted CC Bond Formation in the Gas Phase

Cited by 4 publications

References 49 publications

Bond Activation by Metal–Carbene Complexes in the Gas Phase

Bond Activation by Metal–Carbene Complexes in the Gas Phase

Sulfur Dioxide Oxidation by Zinc and Zinc Oxide Nitrate/Nitrite Complexes in the Gas Phase: An Interplay between Redox‐Active Ligands and Metal

Identifizierung eines Zweifach‐Koordinierten Eisen(I)‐Oxalat‐Komplexes

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