Tracking multiple components of a nuclear wavepacket in photoexcited Cu(I)-phenanthroline complex using ultrafast X-ray spectroscopy.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31399565.
- Also identified by DOI 10.1038/s41467-019-11499-w and PMC identifier 6689108.
- 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
Disentangling the strong interplay between electronic and nuclear degrees of freedom is essential to achieve a full understanding of excited state processes during ultrafast nonadiabatic chemical reactions. However, the complexity of multi-dimensional potential energy surfaces means that this remains challenging. The energy flow during vibrational and electronic relaxation processes can be explored with structural sensitivity by probing a nuclear wavepacket using femtosecond time-resolved X-ray Absorption Near Edge Structure (TR-XANES). However, it remains unknown to what level of detail vibrational motions are observable in this X-ray technique. Herein we track the wavepacket dynamics of a prototypical [Cu(2,9-dimethyl-1,10-phenanthroline)<sub>2</sub>]<sup>+</sup> complex using TR-XANES. We demonstrate that sensitivity to individual wavepacket components can be modulated by the probe energy and that the bond length change associated with molecular breathing mode can be tracked with a sub-Angstrom resolution beyond optical-domain observables. Importantly, our results reveal how state-of-the-art TR-XANES provides deeper insights of ultrafast nonadiabatic chemical reactions.