Mono‐, Di‐ and Trinuclear Dioxo Complexes of Uranium Containing Hydrazonato and Azomethine Ligands

Mono‐, di or trinuclear dioxouranium complexes with benzoylhydrazonato or azomethine ligands were prepared by reactions of common dioxouranium precursors such as UO 2 (NO 3 ) 2 · 6 H 2 O or [NBu 4 ] 2 [UO 2 Cl 4 ] with vanillin benzoylhydrazone (H 2 L 4 ), salicylaldehyde benzoylhydrazone (H 2 L 5 ), 2‐hydroxyacetylbenzene salicylhydrazone (H 3 L 6 ) or N‐(2‐ethoxycarbonyl‐3‐oxo‐but‐1‐en(1)yl)‐2‐aminophenol (H 2 L 7 ). Spectroscopic and X‐ray crystallographic studies on the complexes [NBu 4 ] 2 [UO 2 Cl 4 ] · 2 H 2 L 4 , [UO 2 (HL 5 )(H 2 L 5 ) 2 ](NO 3 ), [HNEt 3 ] 2 [{UO 2 (L 6 )} 2 ] and [HNEt 3 ] 2 [{UO 2 (L 7 } 3 O] confirm that the individual donor atom constellation, the size of the potential chelate rings and the acidity of the OH and NH functionalities of the proligands have a strong influence on the structure of the products.