C–H Bond Activation ofMethane with Gaseous [(CH₃)Pt(L)]⁺ Complexes (L = Pyridine, Bipyridine, and Phenanthroline)

Abstract

+ also bring about activation of methane, though at a lower rate, whereas the bipyridine complex [(CH 3 )Pt(py) 2 ] + does not react with methane at thermal conditions. A detailed analysis of the experimental data by means of kinetic modeling provides insight into the underlying mechanistic steps, but a distinction whether the reaction occurs as σ bond metathesis or via an oxidative addition cannot be made on the basis of the experimental data available.

On the Mechanisms of Degenerate Ligand Exchange in [M(CH3)]+/CH4 Couples (M=Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt) as Explored by Mass Spectrometric and Computational Studies: Oxidative Addition/Reductive Elimination versus σ‐Complex‐Assisted Metathesis

“…(2b)] has been verified, and for M=Rh and Pd the reaction efficiencies are comparable to those measured for their deuterated analogues, whereas for the [Pt(CH 3 )] + / 13 CH 4 system we note a drop in reactivity. This finding is in line with the hydrogen/deuterium scrambling results, which are rather extensive for the [Pt(CH 3 )] + /CD 4 couple, thus demonstrating the operation of a set of forward/backward reactions; of course, these do not show up in the experiment with 13 CH 4 31d. Finally, from Table 2 we note a very close labeling distribution for the [Pt(CH 3 )] + /CD 4 couple irrespective of the mode of [M(CH 3 )] + formation, that is, through reacting atomic M + with CH 3 I (FTICR) or generation from solutions of platinum halides in CH 3 OH (ESI); this finding suggests that we are probing the inherent features of the reactions.…”

Competitive Intramolecular Aryl‐ and Alkyl‐CH Bond Activation and Ligand Evaporation from Gaseous Bisimino Complexes [Pt(L)(CH3)((CH3)2S)]+ (L=C6H5NC(CH3)C(CH3)NC6H5)

“…One primary fragment corresponds to the loss of methane, ], and the second to a combined elimination of dimethyl sulfide and methane, [1 -(CH 3 ) 2 S/CH 4 ]. Even at the detection limit of the mass spectrometer, we do not observe a fragment ion that corresponds to the loss of only (CH 3 ) 2 S, i.e., [1 -(CH 3 ) 2 S], although such a species is formed using other ligands L, as for example 2,2'-bipyridine or 1,10-phenanthroline [7]. As expected, the extent of fragmentation increases with increasing the cone voltage (U c ) which determines the amount of energizing collisions occurring in the source region [12] [20] [21].…”

“…91 (2008-Vol. 91 ( ) 1902 2008 Verlag Helvetica Chimica Acta AG, Zürich 1 ) For the thermal gas-phase reactions of these complexes with methane, see [7]. 2 ) For other examples of intramolecular suicidal oxidations of chelating ligands by the transitionmetal core, see [9] and [10].…”

“…Scheme 27 ) For a related case where the CÀH-activation process is preceded by ligand loss, see[26].…”

Thermal NH Bond Activation on Anionic and Cationic Platinum Clusters: Non‐Predetermined Reaction Pathways Indicate Transitions to a Bulk Surface Reactivity

“…[29,30] Efficiently probed with mass spectrometric methods were also various aspects of CÀH bond activation in methane by platinum complexes. [31][32][33] Motivated by the recent discovery that gold nanoparticles exhibit catalytic activity, [34,35] also the interaction of gold clusters with ammonia was investigated computationally. [36] In the present work, we extend the existing experimental reactivity studies [11] with ammonia to anionic platinum clus-…”