HEGER, Dominik, Jana KLÁNOVÁ and Petr KLÁN. Enhanced Protonation of Cresol Red in Acidic Aqueous Solutions Caused by Freezing. Journal of Physical Chemistry B. USA: The American Chemical Society, 2006, vol. 110, No 3, p. 1277-1287. ISSN 1089-5639.
Other formats:   BibTeX LaTeX RIS
Basic 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
Original language English
Type of outcome Article in a journal
Field of Study 10401 Organic chemistry
Country of publisher United States of America
Confidentiality degree is not subject to a state or trade secret
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 cresol red, ice, Photochemistry, spectroscopy
Tags International impact
Changed by Changed by: prof. RNDr. Petr Klán, Ph.D., učo 32829. Changed: 23/6/2009 15:17.
Abstract
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.
Abstract (in Czech)
Protonace Kresolové červeně v zamrzlých vodných roztocích
Links
GA205/05/0819, research and development projectName: Environmentální důsledky fotochemických transformací v ledu a sněhu
Investor: Czech Science Foundation, Enviromental consequences of photochemical processes in ice and snow
MSM0021622412, plan (intention)Name: Interakce mezi chemickými látkami, prostředím a biologickými systémy a jejich důsledky na globální, regionální a lokální úrovni (INCHEMBIOL) (Acronym: INCHEMBIOL)
Investor: Ministry of Education, Youth and Sports of the CR, Interactions among the chemicals, environment and biological systems and their consequences on the global, regional and local scales (INCHEMBIOL)
PrintDisplayed: 26/7/2024 20:26