Direct Probe of Vibrational Fingerprint and Combination Band Coupling

Ryan P McDonnell; Kelson Oram; Mark A Boyer; Daniel D Kohler; Kent A Meyer; Edwin L Sibert Iii; John C Wright

doi:10.1021/acs.jpclett.4c00297

Direct Probe of Vibrational Fingerprint and Combination Band Coupling

J Phys Chem Lett. 2024 Apr 11;15(14):3975-3981. doi: 10.1021/acs.jpclett.4c00297. Epub 2024 Apr 3.

Authors

Ryan P McDonnell¹, Kelson Oram¹, Mark A Boyer¹, Daniel D Kohler¹, Kent A Meyer¹, Edwin L Sibert Iii¹, John C Wright¹

Affiliation

¹ Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin - Madison, Madison, Wisconsin 53706, United States.

PMID: 38569133
DOI: 10.1021/acs.jpclett.4c00297

Abstract

Vibrational fingerprints and combination bands are a direct measure of couplings that control molecular properties. However, most combination bands possess small transition dipoles. Here we use multiple, ultrafast coherent infrared pulses to resolve vibrational coupling between CH₃CN fingerprint modes at 918 and 1039 cm^-1 and combination bands in the 2750-6100 cm^-1 region via doubly vibrationally enhanced (DOVE) coherent multidimensional spectroscopy (CMDS). This approach provides a direct probe of vibrational coupling between fingerprint modes and near-infrared combination bands of large and small transition dipoles in a molecular system over a large frequency range.