1988 Volume 4 Issue 1 Pages 43-47
A series of bis(diphenylphosphinyl)alkanes (DPPO)2R, where R can be p-xylene-α, α′-diyl and (CH2)n(n=1-6, 8 and 10), has been prepared and employed to investigate the solvent extraction of gallium(III) from hydrochloric acid solutions. These bis-type ligands have been found to be more effective than the monodentate ligand, triphenylphosphine oxide (TPPO). The percentage extraction of gallium(III) with these ligands increases with increasing the acidity of the aqueous phase. The extractabilities of the bis-type ligands (DPPO)2(CH2)n depend on the methylene length and increase in the order n=1<2<3_??_6, 8 and 10. The molar ratios of the extractant to gallium(III) in the extracted species are determined to be 1:1 for TPPO and 2:1 as well as 1:1 for the bis-type ligands. These ratios depend on the initial extractant concentration in the organic phase. The extraction constants are log Kex=2.5, 5.4 and 4.8 for TPPO, (DPPO)2(p-xyl) and (DPPO)2(CH2)3, respectively.
