Effect of amino group protonation on the carboxyl group in aqueous glycine observed by O 1s X-ray emission spectroscopy
(2018) In Physical chemistry chemical physics : PCCP 20(36). p.23214-23221- Abstract
The valence electronic structures of the amino acid glycine in aqueous solution were investigated in detail through X-ray emission spectroscopy at O 1s excitation under selective excitation conditions of the C[double bond, length as m-dash]O site in the carboxyl group. The X-ray emission spectra of glycine were similar to that of acetic acid (CH3COOH), suggesting a resemblance between the molecular orbitals associated with the carboxyl groups in the two molecules. The changes of O 1s X-ray emission spectra as a function of pH were investigated in detail. In addition to spectral changes due to protonation/deprotonation of the carboxyl group for lower pH-values around the pKa value (∼2.3), the spectra of glycine exhibited further changes... (More)
The valence electronic structures of the amino acid glycine in aqueous solution were investigated in detail through X-ray emission spectroscopy at O 1s excitation under selective excitation conditions of the C[double bond, length as m-dash]O site in the carboxyl group. The X-ray emission spectra of glycine were similar to that of acetic acid (CH3COOH), suggesting a resemblance between the molecular orbitals associated with the carboxyl groups in the two molecules. The changes of O 1s X-ray emission spectra as a function of pH were investigated in detail. In addition to spectral changes due to protonation/deprotonation of the carboxyl group for lower pH-values around the pKa value (∼2.3), the spectra of glycine exhibited further changes in the higher-pH region near the pKb value of glycine (dissociation constant of amino group ∼9.5). These results show the effects of amino group protonation on the electronic state around the carboxyl group. X-ray emission spectroscopy might be a tool to investigate intramolecular interactions between functional groups in a molecule.
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- author
- Horikawa, Yuka ; Tokushima, Takashi LU ; Takahashi, O ; Harada, Yoshihisa ; Hiraya, A and Shin, S
- publishing date
- 2018-09-19
- type
- Contribution to journal
- publication status
- published
- in
- Physical chemistry chemical physics : PCCP
- volume
- 20
- issue
- 36
- pages
- 8 pages
- publisher
- Royal Society of Chemistry
- external identifiers
-
- scopus:85053825683
- pmid:30039134
- ISSN
- 1463-9084
- DOI
- 10.1039/c7cp08305j
- language
- English
- LU publication?
- no
- id
- ac880e48-f5f6-49ff-8c0c-aab0e2b7d26a
- date added to LUP
- 2019-05-03 16:45:54
- date last changed
- 2024-03-03 04:29:09
@article{ac880e48-f5f6-49ff-8c0c-aab0e2b7d26a,
abstract = {{<p>The valence electronic structures of the amino acid glycine in aqueous solution were investigated in detail through X-ray emission spectroscopy at O 1s excitation under selective excitation conditions of the C[double bond, length as m-dash]O site in the carboxyl group. The X-ray emission spectra of glycine were similar to that of acetic acid (CH3COOH), suggesting a resemblance between the molecular orbitals associated with the carboxyl groups in the two molecules. The changes of O 1s X-ray emission spectra as a function of pH were investigated in detail. In addition to spectral changes due to protonation/deprotonation of the carboxyl group for lower pH-values around the pKa value (∼2.3), the spectra of glycine exhibited further changes in the higher-pH region near the pKb value of glycine (dissociation constant of amino group ∼9.5). These results show the effects of amino group protonation on the electronic state around the carboxyl group. X-ray emission spectroscopy might be a tool to investigate intramolecular interactions between functional groups in a molecule.</p>}},
author = {{Horikawa, Yuka and Tokushima, Takashi and Takahashi, O and Harada, Yoshihisa and Hiraya, A and Shin, S}},
issn = {{1463-9084}},
language = {{eng}},
month = {{09}},
number = {{36}},
pages = {{23214--23221}},
publisher = {{Royal Society of Chemistry}},
series = {{Physical chemistry chemical physics : PCCP}},
title = {{Effect of amino group protonation on the carboxyl group in aqueous glycine observed by O 1s X-ray emission spectroscopy}},
url = {{http://dx.doi.org/10.1039/c7cp08305j}},
doi = {{10.1039/c7cp08305j}},
volume = {{20}},
year = {{2018}},
}