Solvent Extraction Behavior of Platinum(IV) and Palladium(II) as Chlorocomplex Acids with Trioctylphosphine Oxide

Abstract

In order to compare the extractions of platinum(IV) and palladium(II) complex acids with trioctylphosphine oxide (TOPO) to those of other inorganic acids, the distribution ratio of these metals between o-xylene containing TOPO and 4.0mol/dm³ (Na, H)(Cl, HSO₄) has been measured at 298K. The extraction curves can be explained by the assumption that the dominant extracted species ratio of either platinum(IV) or palladium(II) would be 2:1:4 for proton:chlorocomplex anion:TOPO, at least in 4.0mol/dm³ chloride media. The extraction constants have been determined to be 10^5.01 for platinum(IV) and 10^4.04 for Palladium(II).