The impact of the vibrational coupling of the OH stretch mode on the spectra differs significantly between IR and Raman spectra of water. Unified understanding of the vibrational couplings is not yet achieved. By using a different class of vibrational spectroscopy, hyper-Raman (HR) spectroscopy, together with machine-learning-assisted HR spectra calculation, we examine the impact of the vibrational couplings of water through the comparison of isotopically diluted HO and pure HO. We found that the isotopic dilution reduces the HR bandwidths, but the impact of the vibrational coupling is smaller than in the IR and parallel-polarized Raman. Machine learning HR spectra indicate that the intermolecular coupling plays a major role in broadening the bandwidth, while the intramolecular coupling is negligibly small, which is consistent with the IR and Raman spectra. Our result clearly demonstrates a limited impact of the intramolecular vibration, independent of the selection rules of vibrational spectroscopies.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.jpclett.3c00398 | DOI Listing |
J Phys Chem A
January 2025
University of Göttingen, Institute for Physical Chemistry, Tammannstraße 6, 37077,Göttingen Germany.
Rotational spectroscopy is an excellent tool for structure determination, which can provide additional insights into local electronic structure by investigating the hyperfine pattern due to nuclear quadrupole coupling. Jet-cooled molecules are good experimental benchmark targets for electronic structure calculations, as they are free of environmental effects. We report the rotational spectra of 2-chlorobenzaldehyde, 3-chlorobenzaldehyde, and 4-chlorobenzaldehyde, including a complete experimental description of the nuclear quadrupole coupling constants, which were previously not experimentally determined.
View Article and Find Full Text PDFNat Chem
January 2025
Department of Chemistry, University of California Irvine, Irvine, CA, USA.
Controlling reaction outcomes through external influences is a central goal in chemistry. Vibrational coupling between molecular vibrations and cavity modes is rapidly emerging as a distinct strategy compared with conventional thermochemical and photochemical methods; however, insight into the fundamental mechanisms remains limited. Here we investigate how vibrational weak and strong coupling in plasmonic nanocavities modifies the thermal dehydration of copper sulfate pentahydrate.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States.
The cyano-cyclopentadiene molecule (CN-CH) has attracted significant interest since its detection in the interstellar medium, but the radical (CN-CH) and anionic (CN-CH) forms of cyano-cyclopentadiene have not been studied. The cyano-cyclopentadienyl radical (CN-Cp) has a strong dipole moment, rendering it an ideal system for vibrational and rotational spectroscopy. We report an investigation of the cryogenically cooled cyano-cyclopentadienide anion (CN-Cp) using high-resolution photoelectron imaging, photodetachment spectroscopy, and resonant photoelectron imaging.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Chemistry, University of California, Davis, One Shields Ave., Davis, California 95616, United States.
Combustion and pyrolysis processes of allene and propyne are known to involve radicals with the structural formula CH, the most stable of which is the classic resonance-stabilized allyl radical. In addition to allyl, four other isomers of CH are possible: the propene derivatives -1-propenyl, -1-propenyl, and 2-propenyl, as well as the cyclopropane derivative cyclopropyl. Among these 5 species, the allyl radical has been extensively studied both theoretically and spectroscopically; however, little is known about the spectroscopy of the cyclopropyl radical, and virtually no experimental spectroscopic data are available for the remaining three.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain.
We introduce a computational methodology for evaluating and analyzing spin-vibration couplings in molecular systems, enabling insights into the interplay between electronic spins and molecular vibrations. By mapping ab initio electronic structure calculations onto molecular spin Hamiltonians, our approach captures those vibrational interactions potentially driving spin relaxation process. Spin-vibration couplings, derived from Holstein and Peierls terms, highlight the pivotal role of vibrational mode symmetry in spin decoherence and efficient energy dissipation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!