Low oxidation state actinide heterolide complexes

该项目旨在开发低氧化态（OS）锕系离子（An2+和An3+）的化学性质，以更深入地了解影响其价电子构型（VEC）、成键和反应性的性质，以及由不同的VEC驱动的不同化学潜力。当代低OS，锕系化学已经定义了两类An2+和An3+离子，其中VEC可以用以下两种形式来描述：fn+1或fnd1（注意，这些只是描述了这些离子中最外层电子配置的近似）。在某些情况下，同一种金属在不同的配位环境中存在这两种情况。在这里，我们将利用一种模块化的分子设计，使用软供体配体来靶向低OS锕系离子，这种配体允许在最小的配位环境变化下改变单个变量（杂原子的身份）。这将使我们对这些离子的物理化学性质以及控制它们稳定性的因素有前所未有的了解。我们将通过以下方式实现这一目标：1)使用模块化框架合成低OS f嵌段配合物，其中配体供体原子可以在最小程度上改变整体立体化学性质；2)使用能够进行高级光谱表征的供体元素；3)通过磁性（SQUID）、磁共振（NMR， EPR）、x射线吸收光谱（金属边缘）表征分子，加深对其电子结构的理解。这种系统的方法尚未应用于这个新兴的研究领域，是扩大其前沿的合乎逻辑的下一步。这项工作将产生基础知识，为未来的工作提供信息，以控制f块离子的构型，以及氧化还原驱动的镧系/锕系化学。问题：我们可以使用新的软供体配体来分离低氧化态和锕系配合物吗？这些配合物的电子结构是什么，电子密度是在金属上还是在配体上？这是否随供体类型而改变？这些低氧化态络合物是像传统的锕系络合物一样反应，还是更像过渡金属？方法：设计合成配体。使配合物处于容易得到的氧化态。将络合物还原到较低的形式氧化态。用最先进的实验和理论方法来描述。使用经典过渡金属反应类研究反应性。职权范围/主题：合成配位化学/计算和理论化学。凝聚态物质：电子结构。凝聚态物质：磁性和磁性材料。

This project seeks to develop the chemistry of low oxidation state (OS) actinide (An2+ and An3+) ions towards a deeper understanding of the properties that affect their valence electron configuration (VEC), bonding, and reactivity, and the potential for divergent chemistry driven by different VECs. Contemporary low OS, actinide chemistry has defined two classes of An2+ and An3+ ion where the VEC can be described using the following two formalisms: fn+1 or fnd1 (note that these simply describe an approximation of the configuration of the outermost electrons in these ions). In some cases both exist for the same metal with different coordination environments. Here we will exploit a modular molecular design to target low OS actinide An ions using soft donor ligands which allow a single variable (the identity of a heteroatom) can be changed with minimal changes to the coordination environment. This will afford unprecedented insight into the physicochemical properties of these ions, and the factors which govern their stabilities. We will achieve this by:1) synthesising low OS f-block complexes using modular frameworks where ligand donor atoms can be altered with minimal changes to the overall stereochemical properties; 2) using donor elements which are amenable to advanced spectroscopic characterisation;3) characterising molecules by magnetism (SQUID), magnetic resonance (NMR, EPR), X-ray absorption spectroscopy (at metal edges), to deepen understanding of their electronic structure. This systematic approach has not yet been applied to this nascent research area and is a logical next step to expand its frontier. This work will produce fundamental knowledge to inform future work into configuration control of f-block ions, and redox-driven lanthanide/actinide chemistry.Questions:Can we use novel soft-donor ligands to isolate low-oxidation state and actinide complexes?What is the electronic structure of these complexes, does the electron density reside on the metal or ligand?Does this change with the donor type?Do these low oxidation state complexes react like traditional actinide complexes, or more like transition metals?Approach:Design and synthesize ligands.Make complexes in readily available oxidation states.Reduce complexes to lower formal oxidation states.Characterize using state of the art experimental and theoretical approaches.Study reactivity using classical transition metal reaction classes.Remit / themes:Synthetic coordination chemistry/Computational and theoretical chemistry.Condensed matter: electronic structure.Condensed matter: magnetism and magnetic materials.