Quenching of uranyl luminescence by neptunium ions in solution

Journal Article · · Sov. Radiochem. (Engl. Transl.); (United States)

OSTI ID:6822030

Yusov, A B; Krot, N N; Karelin, V V; Ivanov, L N

A study has been made of the luminescence of uranyl in sulfuric and phosphoric acid solutions in the presence of neptunium(V), (VI), and (VII). Curves have been obtained for the intensity I and lifetime tau of luminescence as functions of the neptunium concentration. From the decrease in I and tau, the respective Stern-Volmer quenching constants K/sub I/ and K/sub tau/ have been determined. The constants lie within the range from 10/sup 2/ to 6 X 10/sup 4/ (moles/liter)/sup -1/. The neptunium(V) is the strongest quenching agent of the uranyl luminescence. In quenching by neptunium(VI) and neptunium(VII), the Stern-Volmer equation is followed only for the change in tau: the decrease of intensity when the neptunium is added is more rapid. Such a character of quenching is explained by resonance transfer of energy from the UO/sub 2//sup 2 +//sup */ ion to the neptunium(VI) or (VII) ion. The quenching by neptunium (V) evidently proceeds through the redox reaction UO/sub 2//sup 2 +/=/sup */ + NpO/sub 2//sup +//sup */ ..-->.. UO/sub 2//sup +/ + NpO/sub 2//sup 2 +/. The luminescence lifetimes have been measured for uranyl in H/sub 2/SO/sub 4/ and H/sub 3/PO/sub 4/ solutions of various concentrations in the absence of quenching agents, and the luminescence quenching rate constants K/sub I/ = (K/sub I//tau/sub 0/) and K/sub tau/ = (K/sub tau//tau/sub 0/ have been calculated.

• OSTI ID: 6822030
• Journal Information: Sov. Radiochem. (Engl. Transl.); (United States), Journal Name: Sov. Radiochem. (Engl. Transl.); (United States) Vol. 25:2; ISSN SVRDA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ACTINIDE COMPOUNDS
CATIONS
CHARGED PARTICLES
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IONS
LUMINESCENCE
NEPTUNIUM COMPOUNDS
PHOSPHORIC ACID
QUENCHING
SULFURIC ACID
TRANSURANIUM COMPOUNDS
URANIUM COMPOUNDS
URANYL COMPOUNDS