STRUCTURAL STUDY OF HOLMIUM(III) AND URANIUM(VI) ORGANIC LIGAND COMPLEXES BY EXTENDED X-RAY ABSORBTION FINE-STRUCTURE SPECTROSCOPY

The structures of holmium-organophosphorus mono- and bidentate ligands and uranium-monoamide ligand complexes in solutions were determined b y extended X-ray absorption fine-structure spectroscopy. The diphosphi ne dioxide coordinates directly to holmium with symmetric bidentate mo de, while the carbamoyl phosphine oxide with asymmetric bidentate mode . The structure for uranium-N,N-dihexyl-3-ethylhexanamide complex is v ery similar to that for the aqua nitrate uranyl complex in bond distan ce and coordination number. (C) 1998 Elsevier Science S.A.