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.