Thiosemicarbazone Complexes of UraniumDedicated to Professor Joachim Strähle on the Ocassion of his 65th Birthday

Abstract

Acetylpyridine thiosemicarbazone, HAPTSC (1), reacts with uranyl nitrate in MeOH under formation of (H 2 APTSC) 2 -[UO 2 (NO 3 ) 2 (µ-OH)] 2 (2) or [ UO 2 (APTSC)(MeOH)(MeO)] 2 (3) depending on the experimental conditions applied. Protonation of 1 and precipitation of the [UO 2 (NO 3 ) 2 (µ-OH)] 2 2Ϫ dianion as acetylpyridinium thiosemicarbazone salt is observed when the reaction is performed without the addition of a base. The metal atoms are situated in the centres of distorted hexagonal bipyramids. The UϪU distance is 3.892(1) Å . Addition of triethylamine results in deprotonation of HAPTSC and the formation of 3 which is an unusual dimer with four methanol/ methanolato ligands of two metal sites sharing two protons. The

Syntheses and structures of 2-acetylpyridine-(2-amino-benzoylhydrazone) and its dioxouranium(VI) complex

“…The molecules are packed in layers parallel to the ac plane and are held together essentially by van 3 ) when the reaction is performed in dmf and the product is crystallized from that solvent. The hydrazone binds in its mono-deprotonated form.…”

“…1,2 As part of our systematic studies on the coordination chemistry of the early actinide elements, we recently published a report on the structural chemistry of thiosemicarbazonato complexes of uranium(VI). 3 The formation of complexes with moderate stability is observed with acetylpyridine thiosemicarbazone. The presence of the pyridine nitrogen atom is essential for the formation of chelate complexes.…”

Studies on bismuth(III) complexes of ligands containing nitrogen/sulfur and extractive procedure for determination of Bi(III)

“…Sulfur compounds have great interest due to their ability to form stable chelates with essential metal ions in which the fungus needs its metabolism [1][2][3][4]. Some thiosemicarbazones serve as models for enzymes and are used as effective oxidants and catalysts [5,6].…”

Synthesis and structures of dioxouranium complexes with 2-pyridineformamide thiosemicarbazones

“…The water-solubility of the thiosemicarbazone ligands (and of their metal complexes) can be increased when derivatives of 2-pyridineformamide are used instead of 2-acetylpyridine as has been demonstrated for metal ions such as Hg 2þ , Pt 2þ , Cd 2þ and Ni 2þ [3]. Here, we present syntheses and structures of the first dioxouranium complexes with 2-pyridineformamide 3-dimethylthiosemicarbazone (HL 1 [2]. A complex of the composition [UO 2 (L 1 )(MeOH)-(MeO)] 2 with a deprotonated thiosemicarbazonato ligand is formed when the reaction is performed in methanol [4], while a dimeric, hydroxo-bridged compound, [UO 2 (L 1 )(l-OH)] 2 , is the product when a nonprotic solvent such as acetonitrile is used [5].…”

“…Despite thiosemicarbazone complexes of uranium have attracted considerable interest during the recent years [1], there is only one report which contains X-ray structural data of such compounds [2]. This describes the products of reactions of 2-acetylpyridine thiosemicarbazone (HL 2 ) with uranyl nitrate or [NBu 4 ] 2 [UO .…”