Synthesis, structure and reactivity of d- and f-block metal-aluminium heterobimetallic complexes

单金属单位点铂族金属催化剂在均相催化领域占据主导地位。最近，极化杂双金属配合物正在挑战这一经典范式，因为它们能够在两个金属位点上脱域激活/形成键，其中只有一个金属具有氧化还原活性。然而，制备有效的p-/d-嵌段混合催化剂的简便途径尚未实现。本项目旨在解决包含无负载过渡金属（TM），镧系元素（Ln）和锕系元素(An)-铝键的配合物的合成挑战，并通过使用最先进的表征方法确定其电子结构，我们将开发结构导向的反应性曲线，以便在小分子活化化学中利用这类配合物。为了实现这一目标，Mg-Al和Zn-Al杂双金属配合物的合成将用于将Al片段转移到过渡金属上，从而可以使用各种TM前体合成新的TM-Al配合物；由于这些起始材料很容易获得，而且通常可以在商业上获得，因此确保了快速进展。根据电负性，新的TM-Al配合物可分为两类：1)含有Al—TM-+极化键的配合物；2)带有Al-+- tm -极化键的配合物。这些不同的键合场景将促进不同的反应性和催化作用，它们将相互补充和对比。各种TM-Al配合物的合成途径将使我们能够评估直接键合的Al中心对杂双金属催化的影响范围，从不参与某些反应的旁观配体，到调整TM电子特性的例子，与TM中心合作以促进底物活化

Monometallic single-site platinum group metal catalysts predominate the homogeneous catalysis landscape. Recently, polarized heterobimetallic complexes are challenging this classical paradigm as they are capable of delocalizing bond activation/formation over two metal sites, where only one metal is redox active. However, facile synthetic routes to effective mixed p-/d-block catalysts have not yet been realized. This project aims to address this synthetic challenge for complexes containing unsupported transition metal (TM), lanthanide (Ln) and actinide (An)-aluminium bonds, and by determining their electronic structures using state-of-the-art characterization methods, we will develop structure-guided reactivity profiles in order to exploit this class of complex in small molecule activation chemistry.To achieve this, the synthesis of Mg-Al and Zn-Al heterobimetallic complexes and these will be used to transfer the Al fragment to transition metals enabling the synthesis of new TM-Al complexes using a variety of TM precursors; rapid progress is ensured as these starting materials are readily, and often commercially available. Based on electronegativities, the new TM-Al complexes can be divided into two categories: 1) complexes containing a Al--TM-+ polarized bond; and, 2) complexes bearing a Al-+-TM - polarized bond. These different bonding scenarios will promote divergent reactivity and catalysis that will complement and contrast each other. Synthetic access to a diverse range of TM-Al complexes will allow us to assess the range of effects that a directly bonded Al center can have on heterobimetallic catalysis, from spectator ligands that do not participate in some reactions, to examples that tune the electronic properties of the TM, cooperatively engaging with TM centres to facilitate substrate activation