The hydration structure of aqueous carbonic acid from X-ray absorption spectroscopy
Despite much effort, aqueous carbonic acid (H2CO3) remains poorly characterized because it is very short-lived. We describe the detection and characterization of aqueous H2CO3 by X-ray absorption spectroscopy, wherein protonation of a bicarbonate solution continuously generates the acid under ambien...
Published in: | Chemical Physics Letters |
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Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
eScholarship, University of California
2014
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Subjects: | |
Online Access: | https://escholarship.org/uc/item/8km10634 https://escholarship.org/content/qt8km10634/qt8km10634.pdf https://doi.org/10.1016/j.cplett.2014.09.052 |
Summary: | Despite much effort, aqueous carbonic acid (H2CO3) remains poorly characterized because it is very short-lived. We describe the detection and characterization of aqueous H2CO3 by X-ray absorption spectroscopy, wherein protonation of a bicarbonate solution continuously generates the acid under ambient conditions. Accompanying first principles calculations of the carbon K-edge transitions facilitate spectral assignment and interpretation in terms of the H2CO3 π∗ orbital, which exhibits a small (0.2 eV), systematic blueshift relative to that of bicarbonate. These results establish the detailed hydration properties of this short-lived molecule and will thereby facilitate future studies of carbonate chemistry in biological and geological system. |
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