| Autor: |
Kondratenko, N. A., Sherstyuk, V. P. |
| Zdroj: |
Theoretical and Experimental Chemistry; November 1987, Vol. 22 Issue: 6 p656-662, 7p |
| Abstrakt: |
On the basis of the equilibrium reactions between different Cr(VI) oxyanions in water solutions the regions of existence of each oxyanion were determined. Chromate ions exist in water solutions at pH > 8 and hydrochromate and bichromate ions exist at pH < 6; in diluted solutions oxyanions exist mainly in the form of hydrochromate ions and in concentrated solutions in the form of bichromate ions. At low pH < 1 hydrobichromate and dihydrochromate ions appear in the solution (in concentrated and diluted solutions, respectively). The absorption spectra of each Cr(VI) oxyanion under the conditions that correspond to the region of existance of each of them, and the fluorescence and phosphorescence spectra of frozen solutions (77‡K) of the chromate and bichromate ions were studied. Singlet-triplet transitions in Cr(VI) oxyanions were observed for the first time in the absorption and fluorescence spectra. A group theoretical analysis, which made it possible to describe the absorption spectra not only of the well studied chromate ion but also the absorption spectra of the other chromium oxyanions, was performed. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
Full text from SpringerLink