Electronic Spectra and the Mechanism of Complexing of Uranyl Nitrate in Water–Acetone Solutions

Autor: A. P. Zazhogin, A. I. Serafimovich, A. A. Zazhogin, A. I. Komyak
Rok vydání: 2003
Předmět:
Zdroj: Journal of Applied Spectroscopy. 70:827-831
ISSN: 0021-9037
Popis: Based on the analysis of electronic absorption and luminescence spectra, the processes of complexing in an aqueous solution of uranyl nitrate hexahydrate (UO2(NO3)2·6H2O) on gradual addition of small amounts of acetone have been investigated. In a pure aqueous solution, uranyl exists as the UO2·5H2O complex. It is shown that addition of acetone to the solution leads to displacement of some water molecules from the first coordination sphere of uranyl and formation of uranyl nitrate dihydrate complexes, UO2(NO3)2·2H2O. It has been established that the stability of these complexes is determined by the decrease in both the water activity and the degree of hydration of uranyl and nitrate. This is the result of the local increase in the concentration of the molecules of acetone (due to its hydrophobicity) in those regions of the solution in which there are uranyl and nitrate ions. The experimental facts supporting the proposed mechanism are given.
Databáze: OpenAIRE