Thorium(4) and dioxouranium(6) complexes of 4-[(N-acetyl)amino]antipyrine

A series of new complexes of thorium(4) and dioxouranium(6) with 4-[(N-acetyl)amino]antipyrine (AAAP) of the general composition ThX4 x 2AAAP (X=Cl, Br, NO3 or NCS), ThX4 x 3AAAP (X=I or ClO4), UO2X2 x 2AAAP (X=Cl, Br, I, NO3, NCS) or UO2(ClO4)2 x 3AAAP has been isolated in the solid state. The electrical conductance indicates that except thorium(4) perchlorate, iodide and dioxouranium(6) perchlorate complexes, all are non-electrolytes; while Th(ClO4)4 x 3AAAP behaves as a 1:4 electrolyte and ThI4 x 3AAAP and UO2(ClO4)2 x 3AAAP are 1:2 electrolytes. The IR spectra show that in all complexes the ligand coordinates the metal via the pyrazolone carbonyl oxygen and amide oxygen atoms. The probable coordination number of Th(4) is 6, 8 or 12 and of U(6) is 8 or 10 depending on the nature of anions. Thermal properties are also discussed. 4 tabs., 35 refs. (author)