Abstract
The extractant nonylthiourea (NTH) in chloroform has been investigated for the extraction of Pt(IV) from chloride solutions at ionic strength of I = 4.0 M and at 22°C. It has been found that chloride concentration has a negative effect on the extraction equilibrium, while proton concentration has no effect. The numerical analysis of the equilibrium data has shown that the extraction of PtCl 6 2− with NTH can be interpreted by the formation of PtCl4(NTH) and PtCl4(NTH)4 species with their respective equilibrium constants of log K 11 = 5.06 ± 0.01 and log K 14 = 14.12 ± 0.04 in 4 M HCl. FTIR spectra of the free NTH and the NTH–Pt(IV) complex were studied to obtain some information on the interaction between Pt(IV) ions and NTH molecules.