Complexes of uranyl β-diketones with aromatic amine N-oxides

Abstract

A series of complexes of uranyl β-diketones with pyridine N-oxide (PyNO) and its 4-substituted derivatives (4z·PyNO) have been isolated by solvent extraction. The β-diketones used were thenoyl trifluoroacetone (TTA), benzoyl trifluoroacetone (BTFA), benzoylacetone (BA), dibenzoylmethane (DBM), trifluoroacetylacetone (TFAA) and hexafluoroacetylacetone (HFAA), the 4-substituents of the amine N-oxide ranging from the electron withdrawing NO 2 and Cl to the electron releasing CH 3 and OCH 3 groups. The analytical data for these complexes lead to their formulation as UO 2(β-diketone) 2 S where S = PyNO or 4z·PyNO. They are monomeric in benzene and non-electrolytes. Characteristic infrared stretching frequencies and proton magnetic resonance spectra of the complexes are reported and discussed in relation to the “substituent parameter” ( σ +) of the amine N-oxide.