UNCLE: Uranium in Non-Conventional Ligand Environments

元素周期表主要由金属组成，因此金属-金属键的研究对于我们理解化学键合，催化，金属表面化学和磁性是至关重要的。锌-锌和镁-镁单键以及铬-铬四重键和铬-铬五重键的发现就是例证。事实上，过渡金属-过渡金属键现在无处不在。然而，含有共价铀-金属键的铀络合物仅限于“重烷基”铀-锡键，尽管理论预测了非常新颖的键合流形。这个创新项目将建立在我们第一个铀-镓键的初步结果的基础上，以提供共价铀-M键（M =过渡金属或铀）的显着和快速扩展。在这些配合物中，金属作为铀的“非常规”配体，这是新颖的，因为铀化学由更传统的碳、氮、氧或卤化物基配体主导。新的铀-金属配合物将进行详细的结构，光谱和理论研究，以全面建立其稳定性，结构，键合和反应性。早期和晚期金属化学的这种联系将使我们：i）更好地理解周期表底部的化学键合; ii）在小分子活化化学中合作的硬金属和软金属的协同效用; iii）对锕系元素化学的快速和重大贡献，落后于周期表的其他部分。研究铀如何结合，以及它与镧系元素的对比，是模拟高放射性钚和镎的行为和提取的关键，这些钚和镎的放射性太强，无法在传统实验室中处理，但存在于核废料中。此外，通过将可以在硬氧化态和软氧化态之间穿梭的铀直接键合到可以活化碳-氢、碳-氧或氢-氢键的过渡金属，我们的目标是产生协同配合物，其可以以选择性和原子/能量有效的方式精细加工工业C1原料。该项目具有冒险性，极有可能产生对镧系元素和锕系元素化学具有国际意义的结果。

The periodic table is composed mainly of metals, thus the investigation of metal-metal bonds is fundamental to generating step-changes in our understanding of chemical bonding, catalysis, metal surface chemistry, and magnetism. This is exemplified by the discovery of zinc-zinc and magnesium-magnesium single bonds and quadruple rhenium-rhenium and quintuple chromium-chromium bonds. Indeed, transition metal-transition metal bonds are now ubiquitous. However, uranium complexes containing covalent uranium-metal bonds are limited to a 'heavy alkyl' uranium-tin bond even though theory predicts highly novel bonding manifolds. This innovative project will build on our preliminary result of the first uranium-gallium bond to deliver a significant and rapid expansion of covalent uranium-M bonds (M = transition metal or uranium). In these complexes the metal is acting as a 'non-conventional' ligand to uranium, which is novel because uranium chemistry is dominated by more traditional carbon-, nitrogen-, oxygen-, or halide-based ligands. The new uranium-metal complexes will be subjected to detailed structural, spectroscopic and theoretical interrogations in order to comprehensively establish their stability, structure, bonding, and reactivities. This nexus of early- and late-metal chemistry will give us: i) a greater understanding of chemical bonding at the foot of the periodic table; ii) the synergic utility of cooperating hard and soft metals in small molecule activation chemistry; iii) a rapid and significant contribution to actinide chemistry, which lags behind the rest of the periodic table. Studying how uranium bonds, and how it contrasts to lanthanide elements, is key to modelling the behaviour and extraction of highly radioactive plutonium and neptunium, which are too radioactive to handle in conventional laboratories, but which are present in nuclear waste. Additionally, by bonding uranium, which may shuttle between hard and soft oxidation states, directly to transition metals which can activate carbon-hydrogen, carbon-oxygen, or hydrogen-hydrogen bonds we aim to produce synergic complexes which can elaborate industrial C1 feedstocks in selective and atom/energy efficient ways. This project is adventurous and highly likely to generate results of international significance to lanthanide and actinide chemistry.