文摘
New coordination compounds with the formulae UO2(NO3)2(HL1)2 (A), UO2(NO3)(L1)(HL1) (B) and UO2(L2)2(HL2) (C), where HL1 = Cl3CCONHP(O)(N(CH2)5)2, HL2 = Cl3CCONHP(O)(N(Et)2)2, were synthesized and characterized by means of 1H NMR and IR spectroscopy, and X-ray diffraction analysis. It was found that in A the ambidentate HL1 ligands coordinate to the dioxouranium(VI) cations in the neutral form in a monodentate manner via the oxygen atom of the phosphoryl group, by analogy with the previously described UO2(NO3)2(HL2)2 (D), UO2(NO3)2(HL3)2 (E) and UO2(NO3)2(HL4)2 (F), where HL3 = Cl3CCONHP(O)(N(CH2)4)2 and HL4 = Cl3CCONHP(O)(N(Me)(Ph))2. In contrast, in B and C the ligands act in two modes, namely in the neutral HL1 (HL2) form with a monodentate coordination and in a deprotonated L1? (L2?) form with a bidentate coordination via the oxygen atoms of the phosphoryl and carbonyl groups, forming six-membered chelate cycles. The extraction of the dioxouranium(VI) nitrate from HNO3 solutions using HL1, HL2 and HL3 in toluene was carried out.
