Detailed Information on Publication Record
2006
Enhanced Protonation of Cresol Red in Acidic Aqueous Solutions Caused by Freezing
HEGER, Dominik, Jana KLÁNOVÁ and Petr KLÁNBasic information
Original name
Enhanced Protonation of Cresol Red in Acidic Aqueous Solutions Caused by Freezing
Name in Czech
Protonace Kresolové červeně v zamrzlých vodných roztocích
Authors
HEGER, Dominik (203 Czech Republic), Jana KLÁNOVÁ (203 Czech Republic) and Petr KLÁN (203 Czech Republic, guarantor)
Edition
Journal of Physical Chemistry B, USA, The American Chemical Society, 2006, 1089-5639
Other information
Language
English
Type of outcome
Článek v odborném periodiku
Field of Study
10401 Organic chemistry
Country of publisher
United States of America
Confidentiality degree
není předmětem státního či obchodního tajemství
Impact factor
Impact factor: 3.047
RIV identification code
RIV/00216224:14310/06:00015811
Organization unit
Faculty of Science
UT WoS
000235046300030
Keywords in English
Photochemistry; ice; cresol red; spectroscopy
Tags
Tags
International impact
Změněno: 23/6/2009 15:17, prof. RNDr. Petr Klán, Ph.D.
V originále
The protonation degree of cresol red (CR) in frozen aqueous solutions at 253 or 77 K, containing various acids (HF, HCl, HNO3, H2SO4, and p-toluenesulfonic acid), sodium hydroxide, NaCl, or NH4Cl, was examined using UV/Vis absorption spectroscopy. CR, a weak organic diacid, has been selected as a model system to study the acid-base interactions at the grain boundaries of ice. The multivariate curve resolution alternating least-squares method was used to determine the number and abundances of chemical species responsible for the overlaying absorption visible spectra measured. The results showed that the extent of CR protonation, enhanced in the solid state by 2-4 orders of magnitude in contrast to the liquid solution, is principally connected to an increase in the local concentration of acids. It was found that this enhancement was not very sensitive to either the freezing rate or the type of acid used and that CR apparently established an acid-base equilibrium prior to solidification. In addition, the presence of inorganic salts, such as NaCl or NH4Cl, is reported to cause a more efficient deprotonation of CR in the former case and an enhanced protonation in the latter case, being well explained by the theory of Bronshteyn and Chernov. CR thus served as an acid-base indicator at the grain boundaries of ice samples. Structural changes in the CR molecule induced by lowering the temperature and a presence of the constraining ice environment were studied by the absorption and 1H NMR spectroscopies. Cryospheric and atmospheric implications concerning the influence of acids and bases on composition and reactivity of ice or snow contaminants were examined.
In Czech
Protonace Kresolové červeně v zamrzlých vodných roztocích
Links
| GA205/05/0819, research and development project |
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| MSM0021622412, plan (intention) |
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