74091-79-5Relevant articles and documents
Dioxouranium(VI) complexes with 2,6-acetylpyridinebenzoylhydrazones and -semicarbazones
Gatto,Lang, E. Schulz,Jagst,Abram
, p. 4405 - 4412 (2004)
Symmetric and asymmetric benzoylhydrazones and semicarbazones derived from 2,6-diacetylpyridine react with common dioxouranium(VI) compounds to form air-stable complexes. The neutral compounds contain doubly deprotonated ligands and possess uranium atoms with distorted pentagonal-bipyramidal coordination spheres. The equatorial coordination spheres of the metal atoms can be extended by the addition of a monodentate ligand such as pyridine or DMSO. Benzoylhydrazones and semicarbazones derived from 2,6-diacetylpyridine react with common dioxouranium(VI) compounds such as uranyl nitrate or [NBu 4]2[UO2Cl4] to form air-stable complexes. 2,6-Diacetylpyridinebis(benzoylhydrazone) (H2L 1), 2,6-diacetylpyridinebis(N4-phenylsemicarbazone) (H 2L2) and the asymmetric proligand 2,6- diacetylpyridine(benzoylhydrazone)(N4-phenylsemicarbazone) (H2L 3) give yellow products of the composition [UO2(L)]. The neutral compounds contain doubly deprotonated ligands and possess uranium atoms with distorted pentagonal-bipyramidal coordination spheres. The equatorial coordination spheres of the metal atoms can be extended by the addition of a monodentate ligand such as pyridine or DMSO. The uranium atoms in the resulting complexes have hexagonal-bipyramidal coordination environments with the oxo ligands in axial positions. X-ray diffraction studies on [UO2(L 1)(DMSO)], [UO2(L2)], [UO2(L 2)(DMSO)] and [UO2(L3)] show relatively short U-O bonds to the benzoylic oxygen atoms between 2.273(6) and 2.368(5) ?. This suggests a preference of these donor sites of the ligands over their imino and amine functionalities (U-N bond lengths: 2.502(7)-2.671(7) ?). The addition of a sixth ligand to the equatorial coordination sphere results in a lengthening of the metal-pyridine bonds.
