Thiophosphorylated bis-thioureas for competitive bulk liquid membrane transport of some metal ions

Abstract

Eight N-thiophosphorylated bis-thioureas of the common formula Z[NHC(S)NHP(S)(OiPr)₂]₂ [Z = ∅ (1), 1,2-C₆H₄ (2), 1,3-C₆H₄ (3), 1,4-C₆H₄ (4), CH₂(1,4-C₆H₄)₂ (5), O(1,4-C₆H₄)₂ (6), S(1,4-C₆H₄)₂ (7), CH₂(1,4-C₆H₁₀)₂ (8)] have been synthesized and characterized by NMR spectroscopy and elemental analysis. Molecular structures of 3, 4, 5·0.5C₆6H₁₄14, 6·CH₂2Cl₂2 and 8 were elucidated by X-ray diffraction revealing two linear intramolecular hydrogen bonds. Their crystal structures are stabilized by four intermolecular hydrogen bonds, which in turn lead to a polymeric chain formation. Competitive transport experiments involving metal ions from an aqueous source phase through a chloroform membrane into an aqueous receiving phase have been carried out using 1–8 as the ionophore present in the organic phase.