Extraction of scandium with tetraphenyl imidodiphosphate and its sulfur analogues, and the radiation stability of the reagent

Abstract

Solvent extraction of scandium from perchloric or hydrochloric acid aqueous systems into benzene solutions of tetraphenyl imidodiphosphate, (PhO)2P(O)NHP(O)(PhO)2 (HA), and its sulfur analogues containing the P(O)NHP(S) or P(S)NHP(S) groups was studied. Behaving as weak acids in the aqueous phase, the reagents form complex extractable compounds ScA3 with scandium. The extraction constants were measured and found lower for the sulfur analogues than for the oxygen reagent. The configuration changes induced in the reagent by gamma irradiation from a 60Co source were studied by examining the extraction of scandium with it and by 31P NMR measurements. Whereas the changes in the solid reagent are not very marked and appear only at doses in excess of 800 kGy, the reagent dissolved in benzene exhibits configuration changes even on the application of doses at the 10 kGy level. This fact is related to the presence of benzene and dissolved oxygen in the system.

Bridge cleavage reactions of late transition-metal dimers with [Ph2P(E)NP(E′)Ph2]− (E = E′ = S or Se; E = O or S, E′ = S or Se)

“…The co-ordination chemistry of Ph 2 PNHPPh 2 (dppa) and [R 2 P(E)NP(E)R 2 ] Ϫ (E = O, S or Se including some mixed chalcogenide donor atom combinations; R = Ph typically) has attracted widespread attention by ourselves and others. The anion [R 2 P(E)NP(E)R 2 ] Ϫ , closely related to acetylacetonate (acac Ϫ ), forms many complexes with a diverse spectrum of metal ions, and moreover, selected complexes have found important applications in areas such as NMR shift reagents, 11 selective metal extractants 33 and in catalysis. 10 Indeed, very recently the novel tetranuclear silver() cluster [{Ag[Ph 2 P(O)-NP(O)Ph 2 ]} 4 ]ؒ2EtOH reported by Rudler et al 10 was shown, in preliminary studies, to be a promising catalyst for alkene epoxidation.…”

Linear 2-Ethylhexyl Imidophosphoric Esters as Effective Rare-Earth Element Extractants

“…Organophosphorus compounds containing imido groups capable of forming neutral chelate complexes with certain metals are widely used as catalytic systems [1][2][3], biologically active [4], and luminescent metal complexes [5], and in metal extraction processes [6][7][8][9][10][11].…”

Gold(0) and Gold(III) Reactivity towards the Tetraphenyldithioimidodiphosphinic Acid, [Ph2P(S)NHP(S)Ph2]

“…The transition metal chemistry of tetraphenyldithioimidodiphosphinic acid, Ph 2 P(S)NHP(S)Ph 2 (H L ), has received great attention during the past years1 and continues to remain an area of interest since the ligand H L has found applications as a selective extraction agent for metals,2 as a lanthanide NMR shift reagent3 and more recently in catalysis 4. The reaction of H L with metal ions usually leads to deprotonation of the NH group and concomitant formation of the anionic tetraphenyldithioimidodiphosphinate ligand [Ph 2 P(S)NP(S)Ph 2 ] − ( L ) which features the negative charge delocalised throughout the SPNPS skeleton 1.…”