The structural and spectroscopic studies of UO22+ complexes with diethyl benzylphosphonate and diethyl (carboxymethyl)phosphonate in solution and in the solid state

Spectroscopic properties of UO22+ complexes with diethyl benzylphosphonate (C6H5CH2P(O)(OCH2CH3)2) (L1) and diethyl (carboxymethyl)phosphonate ((CH3CH2O)2P(O)CH2COOH) (L2) were investigated using absorption and luminescence spectroscopy. Studied compounds were characterized using CHN microanalytical procedures, infrared spectroscopy and by single crystal X-ray diffraction. Uranyl ion forms with the studied ligands complexes of general formulae [UO2(L1)2(NO3)2] and [UO2(L2)2(NO3)2]. In the crystal structures, the uranyl groups are coordinated in the equatorial plane by six oxygen atoms, and the coordination polyhedra of uranium ions are close to hexagonal bipyramid, with uranyl oxygen atoms in apexes.

Graphical abstractComplexes of uranyl ion with diethyl benzylphosphonate (L1) and diethyl (carboxymethyl)phosphonate (L2) ligands were synthesized and characterized structurally and spectroscopically. In the crystal structures of the complexes [UO2(L1)2(NO3)2] and [UO2(L2)2(NO3)2] the uranyl groups are coordinated in the equatorial plane by six oxygen atoms, and the coordination polyhedra of uranium ions are close to hexagonal bipyramid, with uranyl oxygen atoms in apexes.Figure optionsDownload full-size imageDownload as PowerPoint slide