J 2002

Spectrophtometric Study of Uranyl-oxalate Complexation in Solution

HAVEL, Josef, Julio Arturo SOTO-GUERRERO and Přemysl LUBAL

Basic information

Original name

Spectrophtometric Study of Uranyl-oxalate Complexation in Solution

Authors

HAVEL, Josef (203 Czech Republic, guarantor), Julio Arturo SOTO-GUERRERO (484 Mexico) and Přemysl LUBAL (203 Czech Republic)

Edition

Polyhedron, Velká Británie, Elsevier Science Ltd. 2002, 0277-5387

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10406 Analytical chemistry

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 1.414

RIV identification code

RIV/00216224:14310/02:00008579

Organization unit

Faculty of Science

Keywords in English

Uranyl oxalates; Oxalic acid; UV/VIS spectrophotometry; Speciation; Stability Constants; Aqeous solutions
Změněno: 2/6/2003 14:00, prof. RNDr. Josef Havel, DrSc.

Abstract

V originále

Uranyl-oxalate complex equilibrium in aqueous solution was studied by UV-Vis spectrophotometry. Due to high spectra correlation, derivative spectrophotometry was also applied during the search for the best chemical model. The absorption spectra of all the complexes were calculated and found in a good agreement with theoretical considerations. Overall protonation constants of oxalate, necessary for accurate calculation of uranyl-oxalate formation constants, were also determined under the same conditions and the following values were obtained log Beta_p_1 = 3.83 +/- 0.01; log Beta_p_2 = 4.92 +/- 0.01. Stability constants determined for the [(UO2)(p),(C2O4)(q)](2p-2q) species were: log beta(11) = 6.31 +/- 0.02, log beta(12) = 11.21 +/- 0.07, log beta(13) = 13.8 +/- 0.04, log beta(23) = 18.5 +/- 0.2, log beta(25) = 28.5 +/- 0.1 (I = 3.0 M NaClO4; 25 degreesC). The equilibrium constants were extrapolated to infinite dilution by applying specific ion interaction theory (SIT) and are the following: log beta(11)(0) = 7.41 +/- 0.01, log beta(12)(0) = 11.80 +/- 0.02, log beta(13) (0) = 13.96 +/- 0.07. Formation of polynuclear [(UO2)(2)(C2O4)(3)](2-) and [(UO(2))(2)(C2O4)(5)](6-) species was proved and confirmed independently by conductometry and vapor pressure osmometry.

Links

MSM 143100011, plan (intention)
Name: Struktura a vazebné poměry, vlastnosti a analýza syntetických a přírodních molekulových ansamblů
Investor: Ministry of Education, Youth and Sports of the CR, Structure and character of bonding, properties and analysis of synthetic and natural molecular ensembles