Collect. Czech. Chem. Commun. 1990, 55, 364-371

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

Oldřich Navrátila, Eckhard Herrmannb, Gisbert Grossmannc and Jiří Teplýd

a Department of Inorganic Chemistry, J. E. Purkyně University, 611 37 Brno, Czechoslovakia
b Chemistry Section, Martin Luther University, 4010 Halle-Wittenberg, G.D.R.
c Chemistry Section, Technical University, 8027 Dresden, G.D.R.
d Institute of Nuclear Research, 250 68 Řež near Prague, Czechoslovakia


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.