Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance upgrade on Thursday 4th of May 2017 from 8.00am to 9.00am (BST).

During this time our websites will be offline temporarily. If you have any questions please use the feedback button on this page. We apologise for any inconvenience this might cause and thank you for your patience.

Issue 17, 1995
Previous Article Next Article

A polymorph of carbonic acid and its possible astrophysical relevance


Layers of glassy aqueous solutions of HCO3 and of excess HBr have been deposited sequentially on top of each other at 78 K in the form of droplets, and their reaction was studied in vacuo by FTIR spectroscopy from 78 to 300 K. After pumping-off ice, and excess HBr and its hexahydrate, formation of a polymorph of carbonic acid (β-H2CO3) is observed. On further heating to 250 K, it sublimes and/or decomposes. The polymorph can be converted into the form obtained previously from methanolic solution (α-H2CO3). We further show that β-H2CO3 is the same product reported by Moore and Khanna for proton irradiation of cryogenic CO2–H2O mixtures (Spectrochim. Acta, Part A, 1991, 47, 255). This adds an astrophysical relevance to the properties of carbonic acid, which is discussed for cometary nuclei.

Back to tab navigation
Please wait while Download options loads

Article type: Paper
DOI: 10.1039/FT9959102823
Citation: J. Chem. Soc., Faraday Trans., 1995,91, 2823-2826
  •   Request permissions

    A polymorph of carbonic acid and its possible astrophysical relevance

    W. Hage, A. Hallbrucker and E. Mayer, J. Chem. Soc., Faraday Trans., 1995, 91, 2823
    DOI: 10.1039/FT9959102823

Search articles by author