Dutkiewicz Michał S, Goodwin Conrad A P, Perfetti Mauro, Gaunt Andrew J, Griveau Jean-Christophe, Colineau Eric, Kovács Attila, Wooles Ashley J, Caciuffo Roberto, Walter Olaf, Liddle Stephen T
Department of Chemistry and Centre for Radiochemistry Research, The University of Manchester, Manchester, UK.
Joint Research Centre, European Commission, Karlsruhe, Germany.
Nat Chem. 2022 Mar;14(3):342-349. doi: 10.1038/s41557-021-00858-0. Epub 2022 Feb 10.
Neptunium was the first actinide element to be artificially synthesized, yet, compared with its more famous neighbours uranium and plutonium, is less conspicuously studied. Most neptunium chemistry involves the neptunyl di(oxo)-motif, and transuranic compounds with one metal-ligand multiple bond are rare, being found only in extended-structure oxide, fluoride or oxyhalide materials. These combinations stabilize the required high oxidation states, which are otherwise challenging to realize for transuranic ions. Here we report the synthesis, isolation and characterization of a stable molecular neptunium(V)-mono(oxo) triamidoamine complex. We describe a strong Np≡O triple bond with dominant 5f-orbital contributions and σ > π energy ordering, akin to terminal uranium-nitrides and di(oxo)-actinyls, but not the uranium-mono(oxo) triple bonds or other actinide multiple bonds reported so far. This work demonstrates that molecular high-oxidation-state transuranic complexes with a single metal-ligand bond can be stabilized and studied in isolation.
镎是第一种人工合成的锕系元素，然而，与它更著名的相邻元素铀和钚相比，对其研究较少受到关注。大多数镎化学涉及二氧代镎酰基 motif，并且具有一个金属 - 配体多重键的超铀化合物很少见，仅在扩展结构的氧化物、氟化物或卤氧化物材料中发现。这些组合稳定了所需的高氧化态，否则对于超铀离子来说难以实现。在此，我们报告了一种稳定的分子态镎（V） - 单氧三酰胺胺配合物的合成、分离和表征。我们描述了一种具有主要 5f 轨道贡献且 σ > π 能量顺序的强 Np≡O 三键，类似于末端铀氮化物和二氧代锕酰基，但不同于迄今报道的铀单氧三键或其他锕系多重键。这项工作表明，具有单个金属 - 配体键的分子态高氧化态超铀配合物可以被稳定并单独研究。
