Mixed complex formation of indium with a number of β-diketones has been studied from carbon tetrachloride and xylene media. The extraction of indium by BFA and FFA was studied and the nature of the complexes established. The formation of the mixed complexes with BFA and BA/DBM, FFA and BA as well as BFA and FFA have been studied and their equilibrium constants calculated. The statistical and stabilisation constants have been calculated and interpreted on the basis of the participating ligands.

Extraction of indium, cadmium and thallium by salts of dinonylnaphthalene sulphonic acid was studied from sodium, potassium and calcium media. The results showed that HD and its salts formed aggregates and behaved as liquid cation exchangers. The extent of aggregation was studied by vapour pressure osmometry. A comparison was also made using analogous solid cation exchangers.

The kinetics of the electrochemical reduction of europium(III) in water-N, N dimethyl formamide mixtures in potassium chloride medium has been studied. The formal rate constant for the reduction increases markedly from 10⁻⁴ cm sec⁻¹ in low concentrations to 10⁻² cm sec⁻¹ at high concentrations of the solvent. The effects of solvent on the formal potential and diffusion current are discussed.

Synergism in the extraction of uranium (VI) has been studied in the presence of a mixture of antipyrine and β-diketones like benzoyltrifluoroacetone, trifluoroacetylacetone and furoyltrifluoroacetone. The nature of the extracted species has been ascertained from the variation of logD with pH and the concentrations of the extractants. The equilibrium constants for the synergistic species have been evaluated taking into account the protonation and partition coefficient of antipyrine.

Extraction of uranium (VI) in presence of a mixture of oxine and β-diketones,viz, benzoyltrifluoroacetone, trifluoroacetylacetone, thenoyltrifluoroacetone and furoyltrifluoroacetone was studied. Extraction was found to be higher than that for oxine or β-diketone alone and the loss of uranium due to precipitation by oxine was eliminated completely. The synergistic species was found to be a mixed chelate and the nature of the species and equilibrium constant were evaluated. A correlation between the two phase stability constants and dissociation constants and partition coefficients of the β-diketones was also established.

Mixed chelates of thulium with someβ-diketones like thenoyltrifluoroacetone, benzoyltrifluoroacetone, naphthoyltrifluoroacetone, trifluoroacetylacetone, furolytri-fluoroacetone and dibenzoylmethane have been studied. The nature of the extracted species has been investigated by the method of slope analysis. The statistical stabilisation constants have been evaluated. A linear correlation has been observed between the stability of chelates and properties of the chelating agents.