Femtosecond intramolecular rearrangement of the CH3NCS radical cation

Jacob Stamm; Shuai Li; Bethany Jochim; Stephen H Yuwono; Swati S Priyadarsini; Piotr Piecuch; Marcos Dantus

doi:10.1063/5.0117875

Femtosecond intramolecular rearrangement of the CH₃NCS radical cation

J Chem Phys. 2022 Dec 7;157(21):214304. doi: 10.1063/5.0117875.

Authors

Jacob Stamm¹, Shuai Li¹, Bethany Jochim¹, Stephen H Yuwono¹, Swati S Priyadarsini¹, Piotr Piecuch¹, Marcos Dantus¹

Affiliation

¹ Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.

PMID: 36511542
DOI: 10.1063/5.0117875

Abstract

Strong-field ionization, involving tunnel ionization and electron rescattering, enables femtosecond time-resolved dynamics measurements of chemical reactions involving radical cations. Here, we compare the formation of CH₃S⁺ following the strong-field ionization of the isomers CH₃SCN and CH₃NCS. The former involves the release of neutral CN, while the latter involves an intramolecular rearrangement. We find the intramolecular rearrangement takes place on a single picosecond timescale and exhibits vibrational coherence. Density functional theory and coupled-cluster calculations on the neutral and singly ionized species help us determine the driving force responsible for intramolecular rearrangement in CH₃NCS. Our findings illustrate the complexity that accompanies radical cation chemistry following electron ionization and demonstrate a useful tool for understanding cation dynamics after ionization.