Lanthanides and Actinides in the +1 Oxidation State

镧系元素和锕系元素，统称为f块元素，约占元素周期表的四分之一。这些元素的化学和物理性质是现代社会不可缺少的。镧系元素是各种各样技术应用的核心，从医学成像、计算机硬盘和块状磁铁，到国防技术和光学材料。锕系元素钍、铀和钚用于核裂变反应堆，作为英国净零战略的一部分，这一技术被指定为增长的一部分。镧系和锕系化合物的化学和物理性质在很大程度上取决于金属的氧化态。对于镧系元素，氧化态为+3是普遍存在的，而含有这些元素的氧化态为+2和+4的化合物在有限的情况下是已知的。对于早期的锕系元素，氧化态从+3到+6或+7不等，最近观察到高活性的氧化态+2。该项目将侧重于合成和表征第一批含有镧系元素和早期锕系元素（钍-钚）的难以捉摸的+1或单价氧化态的化合物。PI最近报告的第一个铀(I)化合物标志着通往单价镧系和锕系化合物家族的路线。首先，我们将重点放在单价镧系元素上，旨在合成一系列类似茂金属的夹层化合物，并确定这些不寻常化合物的性质所依赖的因素。同时，我们将合成早期锕系元素（钍、铀、镎和钚）的单价茂金属。该项目的核心目标是将合成化学和结构化学的观察结果与详细的物理表征和理论研究相结合。这种方法将提供对单价f元素的电子结构和化学键的定量洞察，包括离子和共价贡献的描述。结构-性质关系将用于设计反应性研究，重点是使用高还原单价f元素的小分子活化。单价镧系元素的电子结构应该比这些元素在常规氧化态下更多样化。因此，相邻镧系元素的反应性可能会发生对比，可能需要根据镧系元素和锕系元素的收缩来修订f元素化学的标准描述。此外，我们将通过与德国同事的新的国际合作，通过旨在用我们的科学激励公众的参与活动计划，以及通过参与与科学目标相关的各种培训计划，通过苏塞克斯团队成员的职业发展，将影响嵌入到项目中。

The lanthanides and actinides, known collectively as the f-block elements, constitute approximately a quarter of the periodic table. The chemical and physical properties of these elements are indispensable to modern society. Lanthanides are at the heart of a huge variety of technological applications, ranging from medical imaging, computer HDDs and bulk magnets, to defence technology and optical materials. The actinides thorium, uranium and plutonium are used in nuclear fission reactors, a technology earmarked for growth as part of the UK's net-zero strategy.The chemistry and physics of lanthanide and actinide compounds depends strongly on the oxidation state of the metal. For the lanthanides, oxidation state +3 is ubiquitous whereas compounds containing these elements in oxidation states +2 and +4 are known in a limited number of cases. For the early actinides, oxidation states range from +3 up to +6 or +7, and the highly reactive oxidation state +2 has recently been observed. This project will focus on the synthesis and characterization of the first compounds containing the lanthanides and the early actinides (thorium-plutonium) in the elusive +1 or monovalent oxidation state.The PI's recent report of the first uranium(I) compound signposts a route to a family of monovalent lanthanide and actinide compounds. At the outset, we focus on monovalent lanthanides, aiming to synthesize a series of metallocene-like sandwich compounds and to determine the factors upon which the properties of these unusual compounds depends. In parallel, we will synthesize monovalent metallocenes of the early actinides thorium, uranium, neptunium and plutonium.A core goal of the project is to combine observations from synthetic and structural chemistry with detailed physical characterization and theoretical studies. This approach will provide quantitative insight into the electronic structure and chemical bonding of monovalent f-elements, including descriptions of the ionic and covalent contributions. The structure-property relationship will be used to design reactivity studies, with an emphasis on small-molecule activation using highly reducing monovalent f-elements. The electronic structure of monovalent lanthanides should be more diverse than for these elements in conventional oxidation states. As a result, contrasting reactivity for neighbouring lanthanides could occur, potentially requiring standard descriptions of f-element chemistry in terms of the lanthanide and actinide contractions to be revised.In addition, we will embed impact into the project through a new international collaboration with colleagues in Germany, through a programme of engagement activities aimed at inspiring the public with our science, and through the career development of the Sussex team members via participation in various training programmes relevant to the scientific objectives.