Gas-phase chemistry of bare transition-metal ions in comparison

Eller, Karsten; Zummack, Waltraud; Schwarz, Helmut

doi:10.1021/ja00158a019

Cited by 173 publications

(77 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[24,25] After transfer of the ions into the cell of a CMS 47X Fourier-transform ion-cyclotron-resonance mass spectrometer, [26] ; the latter two combinations of isotopomers are not resolved in the broadband detection-mode) was selected by means of the FERETS ion-ejection method. [27] After thermalization with pulsed-in Ar buffer gas, reactions with the leaked-in substrates were studied at variable reaction times.…”

Section: Methodsmentioning

confidence: 99%

Coupling of Methane and Ammonia by Dinuclear Bimetallic Platinum–Coinage‐Metal Cations PtM⁺

2003

Self Cite

View full text Add to dashboard Cite

The activation and functionalization of methane constitute continuing challenges for catalysis. One example of their industrial realization is given by the Degussa process for the large-scale production of hydrogen cyanide from methane and ammonia using platinum as heterogeneous catalyst [Eq. (1)].Our aim is the development of a gas-phase model for this process that may enhance the current mechanistic knowledge [1,2] and thus ultimately contribute to rational catalyst improvement. So far, atomic Pt + , homonuclear clusters Pt m + as well as small heteronuclear clusters Pt m Au n + ions have been studied. [3][4][5][6][7] Whereas all the homonuclear Pt m + clusters investigated achieve CH 4 activation in the first reaction step, [8,9] the C À N coupling of the resulting carbene species Pt m CH 2 + with NH 3 only works for m = 1. [3][4][5] In contrast, the dinuclear cluster mediates CÀN bond formation if one platinum atom is replaced by a gold atom.[6] This finding was ascribed to a particularly well-balanced binding situation in the PtAuCH 2 + species. The bonding is strong enough to afford spontaneous activation of CH 4 on the one hand but does not prevent the CH 2 fragment from coupling with NH 3 on the other.[6] Recent results have shown, however, that the larger bimetallic Pt m Au n + clusters do not mediate the coupling step between the CH 2 moiety and NH 3 , thus pointing to special features of PtAu + . [10] To further elucidate the remarkable role of the second metal in the dinuclear cluster, we have extended our studies to PtCu + and PtAg + . The change from gold to its lighter congeners copper and silver is straightforward in view of their electronic and chemical similarities (note, however, that gold is distinguished from both copper and silver by the operation of much stronger relativistic effects [11] ). As with PtAu + , the reactions with CH 4 , O 2 , and NH 3 are investigated; for comparison, the reactivities of Cu 2 + and Ag 2 + are included

show abstract

Section: Methodsmentioning

confidence: 99%

Coupling of Methane and Ammonia by Dinuclear Bimetallic Platinum–Coinage‐Metal Cations PtM⁺

2003

Self Cite

View full text Add to dashboard Cite

show abstract

“…All experiments were performed using a Spectrospin CMS 47X Fourier Transform ion cyclotron (FTICR) spectrometer, described in more detail elsewhere [18]. In brief, Au ϩ cations were generated by laser desorption/ionization of a gold target and transferred by an array of electric focusing lenses to the FTICR cell situated in a 7 Tesla magnetic field.…”

Section: Methodsmentioning

confidence: 99%

Experimental and theoretical studies of diatomic gold halides

Brown

Schwerdtfeger

Schröder

et al. 2002

J. Am. Soc. Mass Spectrom.

Self Cite

View full text Add to dashboard Cite

The diatomic gold halides AuX are studied by means of Fourier-transform ion cyclotron resonance mass spectroscopy and ab initio theory at a quasi-relativistic CCSD(T) level of theory. A thermokinetic approach is used to determine the bond-dissociation energies of neutral AuCl, AuBr, and AuI as well as cationic AuI ϩ , i.e., D 0 (Au-Cl) ϭ 66 Ϯ 3 kcal/mol, D 0 (Au-Br) ϭ 50 Ϯ 5 kcal/mol, as well as the brackets 52 kcal/mol Ͻ D 0 (Au-I) Ͻ 64 kcal/mol and 54 kcal/mol Ͻ D 0 (Au ϩ -I) Ͻ 66 kcal/mol at 0 K. These values allow an evaluation of previous experimental and theoretical data concerning diatomic gold halides. (J Am Soc Mass Spectrom 2002, 13, 485-492)

show abstract

“…Experiments were performed using a Spectrospin CMS 47X FT-ICR mass spectrometer [28,29] that has recently [30] been equipped with a Smalley-type [31] cluster-ion source developed by Bondybey, Niedner-Schatteburg, and co-workers. [32] Briefly, the fundamental of a pulsed Nd:YAG laser (λ ϭ 1064 nm, Spectron Systems) is focused onto a rotating iron target to generate a hot metal plasma.…”

Section: Methodsmentioning

confidence: 99%

Formation and Reactivity of Gaseous Iron‐Sulfur Clusters

2003

Self Cite

View full text Add to dashboard Cite

The gas‐phase reactions of Fen+ clusters, n = 1−6, with COS and CS2 have been investigated by means of Fourier‐transform ion‐cyclotron resonance mass spectrometry. Whereas CS2 predominantly substitutes one Fe atom, COS exclusively affords multiple sulfur transfer and thus opens a synthetic route to gaseous FenSx+ clusters. In the final products such as Fe2S2+, Fe3S2+, and Fe4S4+, the sulfur atoms appear to occupy multiple coordination sites much like in the analogous biogeneous iron‐sulfur clusters. Bracketing experiments find IE(Fe2S2) = 7.2±0.3 eV besides providing upper limits for IE(Fe3S2) and IE(Fe4S4). In accordance with the low IE(Fe2S2), Fe2S2+ does not activate H2 or small hydrocarbons and only exhibits rather limited reactivity towards more reactive substrates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

show abstract

Gas-phase chemistry of bare transition-metal ions in comparison

Cited by 173 publications

References 0 publications

Coupling of Methane and Ammonia by Dinuclear Bimetallic Platinum–Coinage‐Metal Cations PtM⁺

Coupling of Methane and Ammonia by Dinuclear Bimetallic Platinum–Coinage‐Metal Cations PtM⁺

Experimental and theoretical studies of diatomic gold halides

Formation and Reactivity of Gaseous Iron‐Sulfur Clusters

Contact Info

Product

Resources

About

Gas-phase chemistry of bare transition-metal ions in comparison

Cited by 173 publications

References 0 publications

Coupling of Methane and Ammonia by Dinuclear Bimetallic Platinum–Coinage‐Metal Cations PtM+

Coupling of Methane and Ammonia by Dinuclear Bimetallic Platinum–Coinage‐Metal Cations PtM+

Experimental and theoretical studies of diatomic gold halides

Formation and Reactivity of Gaseous Iron‐Sulfur Clusters

Contact Info

Product

Resources

About

Coupling of Methane and Ammonia by Dinuclear Bimetallic Platinum–Coinage‐Metal Cations PtM⁺

Coupling of Methane and Ammonia by Dinuclear Bimetallic Platinum–Coinage‐Metal Cations PtM⁺