CHELATE FORMATION AND EXTRACTION OF 3-VALENT ACTINIUM AMERICIUM CURIUM AND CALIFORNIUM WITH ACETYL ACETOE AND SOME OF ITS DERIVATIVES

It has been found that Ac3+, Am3+, Cm3+, and Cf3+ with substituted 1.3-diketones RCOCH2COR′ and CHCl3 as organic phase are extracted as 1:3-chelates only, if R = CF3 and R′ is an aromatic group (furyl, thienyl, phenyl, or naphthyl). The distribution coefficient of the chelates is dependent on that of the 1.3-diketone and increases-together with the stability constant β3-in the sequence Ac3+-Am3+-Cm3+-Cf3+. The β-isopropyltropolone chelates are much more stable than the acetylacetonates of the corresponding actinides. The enhanced extraction of Am(TTA)3 and Am(BTA)3 in methylisobutylketone (A) is explained by the formation of the adduct-chelates MeL3· A and MeL3· 2A. The acetylacetone, benzoyl- and thenoyltrifluoracetone chelates of americium were prepared by precipitation reactions. They decompose directly to AmO2 by heating in air. © 1969.