SPECTROPHOTOMETRIC STUDIES ON THE CHELATE FORMATION BETWEEN URANIUM(VI) AND 1-(O-ARSONOPHENYLAZO)-2-NAPHTHOL-3,6-DISULFONATE (THORON) IN AQUEOUS SOLUTION

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Journal fuer Praktische Chemie (East Germany)

DOI:https://doi.org/10.1002/prac.19630200315· OSTI ID:4104420

Sangal, S P; Dey, A K

Three different methods, continuous variations, mole ratio, and slope ratio, were used to establish the composition of the Thoron chelate. Mixtures containing uranyl sulfate and Thoron in different stoichiometric ratios (0: 1, measured. The observations showed that the wavelength of max absorbance of Thoron lies at 485 m mu , whereas the case of mixtures the lambda /sub max/ shifts to 510 m mu . Thus it is clear that only one chelate having lambda /sub max/ at 510 m mu is formed under these conditions. The results of the continuous variations method showed that the composition of the chelate is UO/sub 2/ (Thoron), and this composition was further confirmed by the mole ratio and slope ratio methods. When the absorbances of mixtures containing uranyl sulfate and Thoron in the ratio 1: 1 at different pH were measured at various wavelengths, it was found that the lambda /sub max/ of the chelate (510 m mu ) holds from pH 2.5 to 5.0, indicating that the chelate is stable within this pH range. The maximum color intensity of the chelate at its lambda /sub max/ remains constant between pH 2.5 and 4.0. The donor properties of the azo group are weak, but azo compounds that contain a strong donor group in a position ortho to the azo group form very stable chelate rings. In Thoron there are the hydroxy group and an arsonic group in ortho position to the azo group, which makes it effective as a chelating agent. Both these groups are capable of linking the metal ion by the removal of a proton. When the chelate was studied at pH 3.0, the sulfonic acid groups were not ionized; thus the chelate would be neutral. This was confirmed by passing the chelate through columns of ion-exchange resins; neither H (IR 45) nor OH (IR 120) varieties of Amberlite absorbed the chelate. (TCO)

• Research Organization: Univ. of Allahabad, India
• Sponsoring Organization: USDOE
• NSA Number: NSA-18-012134
• OSTI ID: 4104420
• Journal Information: Journal fuer Praktische Chemie (East Germany), Journal Name: Journal fuer Praktische Chemie (East Germany) Vol. Vol: 20; ISSN JPCEA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
ACIDITY
ADSORPTION
CHELATES
CHEMISTRY
FREQUENCY
ION EXCHANGE
PHOTOMETRY
RADON 220
SOLUTIONS
SPECTRAL SHIFT
SPECTROSCOPY
SULFATES
SULFONIC ACIDS
THORIN
URANIUM COMPLEXES
URANYL COMPOUNDS
WATER