Monitoring the Evolution of Relative Product Populations at Early Times during a Photochemical Reaction.
J Am Chem Soc
; 146(6): 4134-4143, 2024 Feb 14.
Article
in En
| MEDLINE
| ID: mdl-38317439
ABSTRACT
Identifying multiple rival reaction products and transient species formed during ultrafast photochemical reactions and determining their time-evolving relative populations are key steps toward understanding and predicting photochemical outcomes. Yet, most contemporary ultrafast studies struggle with clearly identifying and quantifying competing molecular structures/species among the emerging reaction products. Here, we show that mega-electronvolt ultrafast electron diffraction in combination with ab initio molecular dynamics calculations offer a powerful route to determining time-resolved populations of the various isomeric products formed after UV (266 nm) excitation of the five-membered heterocyclic molecule 2(5H)-thiophenone. This strategy provides experimental validation of the predicted high (â¼50%) yield of an episulfide isomer containing a strained three-membered ring within â¼1 ps of photoexcitation and highlights the rapidity of interconversion between the rival highly vibrationally excited photoproducts in their ground electronic state.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Type of study:
Prognostic_studies
Language:
En
Journal:
J Am Chem Soc
Year:
2024
Document type:
Article