Probing the activated complex of the F + NH<sub>3</sub> reaction via a dipole-bound state.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38719855.
- Also identified by DOI 10.1038/s41467-024-48202-7 and PMC identifier 11079065.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Experimental characterization of the transition state poses a significant challenge due to its fleeting nature. Negative ion photodetachment offers a unique tool for probing transition states and their vicinity. However, this approach is usually limited to Franck-Condon regions. For example, high-lying Feshbach resonances with an excited HF stretching mode (v<sub>HF</sub> = 2-4) were recently identified in the transition-state region of the F + NH<sub>3</sub> → HF + NH<sub>2</sub> reaction through photo-detaching FNH<sub>3</sub><sup>-</sup> anions, but the direct photodetachment failed to observe the lower-lying v<sub>HF</sub> = 0,1 resonances and bound states due apparently to negligible Franck-Condon factors. Indeed, these weak transitions can be resonantly enhanced via a dipole-bound state (DBS) formed between an electron and the polar FNH<sub>3</sub> species. In this study, we unveil a series of Feshbach resonances and bound states along the F + NH<sub>3</sub> reaction path via a DBS by combining high-resolution photoelectron spectroscopy with high-level quantum dynamical computations. This study presents an approach for probing the activated complex in a reaction by negative ion photodetachment through a DBS.