New uranyl(VI) complexes with hydrazones derived from aliphatic and aromatic acid hydrazides containing dihydroxo bridges

Summary Several new uranyl(VI) complexes of hydrazones, derived from formoyl-, acetoyl-, butroyl-, caproyl-, salicyloyl-, oxaloyldi-, malonoyldi-, and adipolyldi-hydrazines and benzaldehyde or salicylaldehyde have been prepared in absolute EtOH and in the presence or absence of AcONa. The complexes have been characterized by elemental analyses, molar conductivities, spectral (u.v., i.r, n.m.r.,) and magnetic measurements. I.r. spectral data suggest that the ligands coordinate in a bi-, tri- and/or tetradentate fashion in the enol form, and that proton displacement proceedsvia the enolized carbonyl oxygen solely in the benzaldehyde hydrazone complexes and through the OH (phenolic) in the salicylaldehyde hydrazone complexes. Moreover, the spectral data show the existence of dihydroxo bridges for benzaldehyde hydrazone complexes. The role of the OH (phenolic) as well as the presence or absence of NaOAc on the properties of the latter complexes is discussed.