Extraction and coordination studies of the unexplored bifunctional ligandcarbamoyl methyl sulfoxide (CMSO) with uranium(vi) and cerium(iii) nitrates. Synthesis and structures of [UO2(NO3)2(PhSOCH2CONiBu2)] and [Ce(NO3)3(PhSOCH2CONBu2)2]

Abstract

The bifunctional carbamoyl methyl sulfoxide ligands, PhCH₂SOCH₂CONHPh (L₁1), PhCH₂SOCH₂CONHCH₂Ph (L₂2), PhSOCH₂CONⁱPr₂ (L₃3), PhSOCH₂CONBu₂ (L₄4), PhSOCH₂CONⁱBu₂ (L₅5) and PhSOCH₂CON(C₈H₁₇)₂ (L₆6) have been synthesized and characterized by spectroscopic methods. The selected coordination chemistry of L₁1, L₃3, L₄4 and L₅5 with [UO₂(NO₃)₂] and [Ce(NO₃)₃] has been evaluated. The structures of the compounds [UO₂(NO₃)₂(PhSOCH₂CONⁱBu₂)] (10) and [Ce(NO₃)₃(PhSOCH₂CONBu₂)₂] (12) have been determined by single crystal X-ray diffraction methods. Preliminary extraction studies of ligand L₆6 with U(VI), Pu(IV) and Am(III) in tracer level showed an appreciable extraction for U(VI) and Pu(IV) in up to 10 M HNO₃ but not for Am(III). Thermal studies on compounds 8 and 10 in air revealed that the ligands can be destroyed completely on incineration. The electron spray mass spectra of compounds 8 and 10 in acetone show that extensive ligand distribution reactions occur in solution to give a mixture of products with ligand to metal ratios of 1 ∶ 1 and 2 ∶ 1. However, 10 retains its solid state structure in CH₂Cl₂.