Beyond local group modes in vibrational sum frequency generation

Hilary M. Chase, Brian T. Psciuk, Benjamin L. Strick, Regan J. Thomson, Victor S. Batista, Franz M. Geiger*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

We combine deuterium labeling, density functional theory calculations, and experimental vibrational sum frequency generation spectroscopy into a form of counterfactual-enabled molecular spectroscopy for producing reliable vibrational mode assignments in situations where local group mode approximations are insufficient for spectral interpretation and vibrational mode assignments. We demonstrate the method using trans-β-isoprene epoxydiol (trans-β-IEPOX), a first-generation product of isoprene relevant to atmospheric aerosol formation, and one of its deuterium-labeled isotopologues at the vapor/silica interface. We use our method to determine that the SFG responses that we obtain from trans-β-IEPOX are almost exclusively due to nonlocal modes involving multiple C-H groups oscillating at the same frequency as one vibrational mode. We verify our assignments using deuterium labeling and use DFT calculations to predict SFG spectra of additional isotopologues that have not yet been synthesized. Finally, we use our new insight to provide a viable alternative to molecular orientation analysis methods that rely on local mode approximations in cases where the local mode approximation is not applicable.

Original languageEnglish (US)
Pages (from-to)3407-3414
Number of pages8
JournalJournal of Physical Chemistry A
Volume119
Issue number14
DOIs
StatePublished - Apr 9 2015

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Beyond local group modes in vibrational sum frequency generation'. Together they form a unique fingerprint.

Cite this