skip to main content

SciTech ConnectSciTech Connect

Title: Molecular hydrogen messengers can lead to structural infidelity: A cautionary tale of protonated glycine

The effects of tagging protonated glycine with either He or between 1 and 14 H{sub 2} molecules on the infrared photodissociation spectra and the ion structure were investigated. Differences in the IR spectra with either a single He atom or H{sub 2} molecule attached indicate that even a single H{sub 2} molecule can affect the frequencies of some vibrational bands of this simple ion. The protonation site is the preferred location of the tag with He and with up to two H{sub 2} molecules, but evidence for H{sub 2} attachment to the hydrogen atom of the uncharged carboxylic acid is observed for ions tagged with three or more H{sub 2} molecules. This results in a 55 cm{sup −1} red shift in the carboxylic acid OH stretch, and evidence for some structural isomers where the hydrogen bond between the protonated nitrogen and the carbonyl oxygen is partially broken; as a result H{sub 2} molecules attached to this site are observed. These results are supported by theory, which indicates that H{sub 2} molecules can effectively break this weak hydrogen bond with three or more H{sub 2} molecules. These results indicate that large spectral shifts as a result of H{sub 2} molecules attachingmore » to sites remote from the charge can occur and affect stretching frequencies as a result of charge transfer, and that tagging with multiple H{sub 2} molecules can change the structure of the ion itself.« less
Authors:
;  [1] ;  [2]
  1. Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne (Switzerland)
  2. Department of Chemistry, University of California, Berkeley, California 94720-1460 (United States)
Publication Date:
OSTI Identifier:
22489574
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ATOMS; CARBONYLS; DISSOCIATION; GLYCINE; HELIUM; HYDROGEN; INFRARED SPECTRA; IONS; ISOMERS; MOLECULES; NITROGEN; OXYGEN; PHOTOLYSIS; VIBRATIONAL STATES