A SPECTROPHOTOMETRIC STUDY OF TRIVALENT ACTINIDE COMPLEXES IN SOLUTIONS .3. AMERICIUM WITH BROMIDE IODIDE NITRATE AND CARBONATE LIGANDS

The light absorption spectra of americium(III) in concentrated aqueous lithium bromide, iodide and nitrate, magnesium iodide, potassium carbonate and nitric acid have been obtained, together with those of extracts into triisooctylammonium nitrate solutions in xylene. Effective stability constants for the first (inner sphere) complex are, log β1* = -1·3 ± 0·1 for AmNO32+ and -3·3 ±0·1 for AmBr2+; the iodide complex is much weaker than the latter. Solubility studies show that [Am(OH)(CO3)3]4- exists in 0·1-0·6 M potassium carbonate solutions. The spectral changes are discussed in terms of the environmental effects on the 5f-5f transitions in americium(III). © 1969.