# Dynamics of carbene formation in the reaction of methane with the tantalum cation in the gas phase.
> 気相におけるタンタルカチオンとメタンの反応によるカルベン生成ダイナミクス


## Abstract

Using a crossed-beam velocity map imaging apparatus designed for transition-metal ion–molecule reactions, this study examined the gas-phase interaction between the tantalum cation (Ta⁺) and methane. Ta⁺ is among the rare atomic transition-metal cations capable of activating methane at room temperature, producing TaCH⁺ and molecular hydrogen via C–H bond cleavage. The reaction proceeds through intersystem crossing from the quintet to the triplet potential energy surface, a hallmark of multi-state reactivity common in transition-metal chemistry. Collision-energy-dependent differential cross sections were measured and compared with minimum energy pathway calculations. Analysis of TaCH⁺ velocity distributions revealed contributions from both indirect and rebound scattering dynamics. These findings were further contextualized by comparison with the previously studied oxygen-transfer reaction between Ta⁺ and carbon dioxide.

### Mechanism

Ta⁺ activates the C–H bond of methane through multi-state reactivity involving intersystem crossing from the quintet to the triplet potential energy surface, yielding a tantalum carbene cation (TaCH⁺) and molecular hydrogen.

## Bibliographic

- **Authors**: Meta M, Huber ME, Birk M, Wedele M, Ončák M, Meyer J
- **Journal**: Faraday Discuss
- **Year**: 2024 (2024-08-27)
- **PMID**: [38764361](https://pubmed.ncbi.nlm.nih.gov/38764361/)
- **DOI**: [10.1039/d3fd00171g](https://doi.org/10.1039/d3fd00171g)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 38764361. https://h2-papers.org/en/papers/38764361
> **Source**: PubMed PMID [38764361](https://pubmed.ncbi.nlm.nih.gov/38764361/)