Thermal Dehydrogenation of Methane by [ReN]⁺

Abstract

The thermal reaction of the diatomic rhenium nitride cation [ReN] with methane has been explored using FT-ICR mass spectrometry complemented by high-level quantum chemical calculations. Mechanistic aspects of the reaction have been addressed to uncover scenarios for the competitive generation of a methylene and a hydrogen cyanide ligand attached to the rhenium center. The role the nitrogen atom plays in the reactive [ReN] /CH couple is elucidated, and the cause of the rather different reactivities of [ReN] and its lighter congener [MnN] is revealed.

Mechanistic Variants in Methane Activation Mediated by Gold(I) Supported on Silicon Oxide Clusters

“…It has been experimentally identified that the bare Au 1–4 + clusters can activate methane through oxidative addition of the C−H bond onto single gold atoms (Au δ+ +CH 4 →HAuCH 3 ), even though the energies of the relevant transition states were generally located above those of the reactants and the intermediates with the [HAuCH 3 ] moiety were thermodynamically very unstable . A lot of effort has been devoted to uncovering the ligand effect on the reactivity of cationic gold by preparation of gold oxide as well as carbide cations and gold‐doped heteronuclear oxide clusters . Completely different mechanisms of gold‐mediated C−H activation have been identified.…”

Selective Nitrogen‐Atom Transfer Driven by a Highly Efficient Intersystem Crossing in the [CeON]+/CH4 System

“…In ad ifferent context, gas-phase CÀNc oupling of NH 3 with methane has served as an instructive model for the largescale DEGUSSA (BMA) [15] and Andrussow [16] processes.F or example,the atomic transition-metal cations M + (M = Rh, W, Os,I r, Pt) [17] as well as diatomic [PtM] + (M = Cu, Ag, Au) [18] consecutively activate methane and ammonia to afford CÀN coupling.A ctivation of methane by [TaN] + generates [Ta-(NCH 2 )] + , [19] while competitive generation of [NRe(CH 2 )] + and [HRe(NCH)] + was observed for the [ReN] + /CH 4 couple. [20] In addition, an unprecedented alkyne/nitrile gasphase metathesis takes place when the ligated nitrido dication complex [LFeN] 2+ (L = 2,6-bis(2-methyl-1,3-diaminopropan-2-yl)pyridine) is reacted with alkynes to form RCN and [LFe(CR)] + . [21] Herein, we report an ovel example in which triatomic [CeON] + selectively delivers its nitrogen atom to methane at ambient temperature;t his reactivity contrasts sharply with that of [CeO 2 ] + ,w hich is thermally inert towards this substrate.M echanistic aspects of the reaction of the [CeON] + /CH 4 couple will be revealed, and the associated electronic origins discussed.…”

Selektive Übertragung eines Stickstoffatoms im [CeON]+/CH4‐System durch hocheffizientes Intersystem Crossing

“…[16] Hierbei aktivieren die atomaren Übergangsmetallkationen M + (M = Rh, W, Os,I r, Pt) [17] sowie die diatomaren Cluster [PtM] + (M = Cu, Ag, Au) [18] Methan und Ammoniak konsekutiv unter C-N-Bindungsknüpfung.F erner bildet [TaN] + unter Methanaktivierung [Ta(NCH 2 )] + , [19] während fürdas Reaktionspaar [ReN] + /CH 4 die kompetitive Erzeugung von [NRe(CH 2 )] + und [HRe-(NCH)] + beobachtet wurde. [20] Eine zuvor nicht beobachtete Alkin/Nitril-Metathese findet darüber hinaus in der Gasphasenreaktion des zweifach geladenen Nitridokomplexes …”