Role Of Adducts In The Solvent Extraction Of Metal Chelates PDF Download

The solvent extraction properties of 1,1,1-trifluoro-2,4-pentanedione (H(tfa)), 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (H(hfa)), 1,1,1,2,2,6,6,6-octafluoro-3,5-hexanedione (H(ofhd)), 1,1,1,2,2,3,3,7,7,7-decafluoro-4,6-heptanedione (H(dfhd)), and 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedione (H(fod)) are described. Distribution ratio-pH curves or percent extracted-pH curves are presented for the extraction of copper, iron, beryllium, cobalt, zinc or other metal ions employing chloroform or benzene solutions of each ligand, and for the effective extraction of divalent and trivalent metals with butanol-H(tfa). Marked enhancement of extraction efficiency of divalent metal ions into chloroform or benzene via isobutylamine adduct formation is also described for most systems. The effect of increasing fluorocarbon chain length resulting in increasing ability to extract the divalent metals zinc and cobalt into chloroform or benzene without the aid of adduct formation is discussed, and extraction systems with the optimum ligand, H(dfhd), are characterized. Syntheses of H(dfhd), H(ofhd), and other ligands are reported, and the physical properties of these and various other fluorine-containing beta-diketones and certain toxicity studies are reviewed. Preliminary work on the direct reaction of ligands with metals in hydrocarbons is presented. (Author).