Gas-phase reactions of tantalum carbide cluster ions with deuterium and small hydrocarbons

Electronic structure of cubic HfxTa1–xCy carbides from X-ray spectroscopy studies and cluster self-consistent calculations

“…The crystal structure of HfC x belongs also to the NaCl-type with the homogeneity range corresponding to 0.56 ≤ x ≤ 1.00 [10]. Tantalum and hafnium carbides reveal some interesting properties in nano-size states: tantalum and hafnium are capable of forming cluster ions Ta m C n + (m = 1-11, n = 1-26) and Hf 8 C 12 + [11][12][13], while neutral clusters Ta m C n (m = 1-6, n = 1-7) were obtained by Heaven et al [14] in a supe-0925-8388/$ -see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2007.08.018 rionic expansion following the reaction of tantalum in a laser absorption source.…”

Potential energy surfaces for the Ta++C2 reaction

“…The reactivity studies of these systems facilitate speculation on the possible isomerization of metal carbides. 3 This approach is based on the chemical properties of species involved in the reaction. 3,4 Little insight into the Ta-C bond is available and its properties are deduced based on the pseudo-oxygen character of the C 2 ligand.…”

“…3 This approach is based on the chemical properties of species involved in the reaction. 3,4 Little insight into the Ta-C bond is available and its properties are deduced based on the pseudo-oxygen character of the C 2 ligand. 1, 3 Theoretical studies can lead to precise information not only on the structural and energetical characteristics of these species but also provide insight on the nature of the TaC n ϩ bonding.…”

“…3,4 Little insight into the Ta-C bond is available and its properties are deduced based on the pseudo-oxygen character of the C 2 ligand. 1, 3 Theoretical studies can lead to precise information not only on the structural and energetical characteristics of these species but also provide insight on the nature of the TaC n ϩ bonding. The results of DLV experiments with isotopically labeled precursors 1 and the similarity in the TaC y ϩ distribution from the DLV experiments and the distribution of other transition metal carbides in the Knudsen effusion mass spectrometry experiments 5,6 suggest that the ions produced by DLV originate from recombination reactions in the laser generated plasma.…”

Methane Activation by Iron-Carbide Cluster Anions FeC6–

“…12−21 The reactions of CH 4 with metal ions such as Os + , 22 Pt n ± , 23 Au 2 + , 24 Ta + , 25 and others 26−28 and metal oxide (hydride) ions such as MgO + , 29 40 Metal carbide species are also proposed to be present as promising centers for CH 4 activation in the condensed-phase system; 41,42 however, the extensive studies of metal carbide species mainly focused on the structure and stability, 43−45 and only two gas-phase examples, TaC y + (y = 1− 14) 46 and MoC + , 47 have been reported to be capable of activating CH 4 . These carbide clusters are positively charged, and CH 4 activation by anions is considered to be difficult under thermal collision conditions.…”