TY - JOUR
AU - Lane Terry
AU - Maddie Klumb
AU - Deacon Nemchick
AU - Robert Hodyss
AU - Frank Maiwald
AU - J. Mathias Weber
AB - We report the infrared photodissociation spectrum of tagged protonated valine in the range 1000–1900 cm–1, prepared in a cryogenic ion trap. Comparison of experimental results with calculated infrared spectra based on density functional theory shows that the hydroxyl group of the carboxylic acid functionality and the protonated amine group adopt a trans configuration. Nitrogen and methane molecules were used as messenger tags with optimal tagging temperatures of 30 K for N2 and 60 K for CH4. While the calculated infrared spectra of the tagged ion suggest only a weak influence of the messenger tag on the frequency positions of ValH+, the measured intensities for N2-tagged ValH+ appear strongly suppressed for all but the highest frequency feature at 1773 cm–1. We trace this behavior to the binding energy of the N2 tag, which is significantly higher than that of CH4, based on density functional and coupled cluster calculations and rate estimates for photoinduced unimolecular dissociation from statistical theory.
BT - The Journal of Physical Chemistry A
DA - 2024-08
DO - 10.1021/acs.jpca.4c03552
IS - 34
M3 - doi: 10.1021/acs.jpca.4c03552
N1 - doi: 10.1021/acs.jpca.4c03552
N2 - We report the infrared photodissociation spectrum of tagged protonated valine in the range 1000–1900 cm–1, prepared in a cryogenic ion trap. Comparison of experimental results with calculated infrared spectra based on density functional theory shows that the hydroxyl group of the carboxylic acid functionality and the protonated amine group adopt a trans configuration. Nitrogen and methane molecules were used as messenger tags with optimal tagging temperatures of 30 K for N2 and 60 K for CH4. While the calculated infrared spectra of the tagged ion suggest only a weak influence of the messenger tag on the frequency positions of ValH+, the measured intensities for N2-tagged ValH+ appear strongly suppressed for all but the highest frequency feature at 1773 cm–1. We trace this behavior to the binding energy of the N2 tag, which is significantly higher than that of CH4, based on density functional and coupled cluster calculations and rate estimates for photoinduced unimolecular dissociation from statistical theory.
PB - American Chemical Society
PY - 2024
SN - 1089-5639
SP - 7137
EP - 7144
EP - 
T2 - The Journal of Physical Chemistry A
TI - Cryogenic Ion Vibrational Spectroscopy of Protonated Valine: Messenger Tag Effects
UR - https://doi.org/10.1021/acs.jpca.4c03552
VL - 128
ER -