A Spectrophotometric Study of Trivalent Actinide Complexes in Solution. IV. Americium with Chloride Ligands

The light absorption spectra of americium(III) in ethanolic and concentrated aqueous lithium chloride solutions, and in long-chain alkylammonium chloride solutions in aromatic diluents were obtained, as well as those of certain solid double salts and complexes. A strong 5f⁶ → 5f⁵6d¹ transition was observed in the aqueous solutions at 235 nm (42,500 cm^?1), and from the dependence of the intensity of this and the 503 nm (19,880 cm^?1) band, on the effective chloride activity, the stability constants of the inner sphere complexes: AmCl²⁺, logβ₁^* = ?2.21± 0.08, and AmCl₂⁺, log β₂^* = ?4.70 ± 0.08, were determined. The spectrum of the long-chain amine extracts is comparable to that of solids of the composition AmCl₃ · 2N(C₄H₉)₄Cl · × LiCl, and the nature of the extracts and of this and similar solids is discussed.