Extraction and separation of Pd(II) by N, N'-diethyl-N, N'-dicyclohexylmalonamide in a nitric acid system

Extraction and Complexation Investigation of Palladium(II) by a Nitrilotriacetate-Derived Triamide Ligand

“…Besides good extraction properties, good stripping properties are also required for a promising extraction system. Sodium carbonate, oxalic acid, and thiourea have been used in the literature to study the stripping of Pd­(II) from the loaded organic phase. − For sodium carbonate, it can react with Pd 2+ to produce a water-insoluble precipitate. For oxalic acid and thiourea, they can form stable complexes with Pd 2+ through strong coordination groups (CS and CO).…”

Agile synthesis and automated, high-throughput evaluation of diglycolamides for liquid–liquid extraction of rare-earth elements

“…For example, the well-established Schotten-Baumann approach requires pre-activating diglycolic acid to diglycolic chloride to promote the amide bond formation with alkyl amines (Scheme 1a). 20 This multi-step method suffers from the use of moisture-sensitive reactants, including thionyl chloride (SOCl 2 ), oxalyl chloride (COCl) 2 and intermediate (diglycolic chloride), and anhydrous solvents with the emission of toxic side-products (SO 2 , CO, and HCl). To overcome the drawbacks of the Schotten-Baumann approach, Verboom and co-workers reported direct amidation of the diglycolic esters mediated by aluminum chloride (AlCl 3 ) (Scheme 1b), 21 allowing the one-step transformation of stable diesters into the desired DGAs and eliminating the preparation of the diglycolic chlorides.…”