Spectroscopic detection of isolated carbonic acid

• Published in: The Journal of Chemical Physics
• Main Authors: Mori, Tetsuya, Suma, Kohsuke, Sumiyoshi, Yoshihiro, Endo, Yasuki
• Format: Article in Journal/Newspaper
• Language: English
• Published: AIP Publishing 2009
• Subjects: Nozzle; Carbonic acid
• Online Access: http://dx.doi.org/10.1063/1.3141405; https://pubs.aip.org/aip/jcp/article-pdf/doi/10.1063/1.3141405/15862732/204308_1_online.pdf

Carbonic acid (cis-trans H2CO3) in the gas phase has been successfully produced in a supersonic jet using a pulsed discharge nozzle, and pure rotational transitions of this molecule have been observed by Fourier-transform microwave spectroscopy. Although the observed cis-trans conformer is not the global minimum structure, it is an important conformer as a starting point of its dissociation to CO2 and H2O. Three deuterated isotopologues of the cis-trans conformer (cis-trans HDCO3, cis-trans DHCO3, and cis-trans D2CO3) have also been observed, yielding the r0 structure of cis-trans H2CO3. The present result is accurate enough to be used in radio astronomical observations.