SubVAR - Sub-Valent Alkaline Earth Reagents

我们的社会依赖化学工业来生产帮助和维持我们现代生活方式的材料。基于相对简单的化学转化的制造过程负责药物、农药、燃料和肥料的生产，并且这些过程围绕氢、一氧化碳和氮等基本构建块构建是很常见的。一个典型的例子是费托工艺，这是最流行的气制液工艺之一，用于从一氧化碳和氢气中生产长链碳氢化合物。英国公司（如Johnson Matthey， BP, Velocys）在开发用于将城市废物和生物质转化为可再生燃料的新型催化剂和FT反应器方面的重大投资证明了其国家战略重要性，这符合英国政府到2030年增加FT工厂数量和合成燃料供应的战略。然而，与这些类型的化学制造过程相关的成本通常非常高，因为它们通常依赖于昂贵且有毒的过渡金属试剂，并且需要非常高的温度和压力。地球上丰富且无毒的金属有望成为化学制造过程中更便宜、更可持续的替代品。然而，基于这些金属的试剂不能分解这些过程中使用的许多小分子，因为它们缺乏氧化还原反应性。尽管如此，近年来在生成氧化还原活性的2族试剂方面取得了许多进展，导致了第一个单价铍、镁和钙的报道。该领域仍处于起步阶段，这些新物种尚未提供可与化学工业使用的传统过渡金属系统相媲美的转化。必须设计新的方法来发现更可持续的替代品和更便宜的试剂，以模仿过渡金属催化剂的性能。该项目将研究碱土家族的基本性质（铍和镭除外）；这些都是地球上丰富的无毒金属，有一天可以为化学工业目前使用的材料提供更可持续的替代品。在初步工作中，我们已经证明了单价碱土配合物可以通过明智和量身定制的分子设计来稳定。我们之前的实验和理论研究提供了一个可转移到该组所有元素的蓝图，并将提供一个新的物种类别，其中重碱土金属具有过渡金属样电子构型，不像以前的亚价2族配合物的例子。这是制备碱性土试剂的关键的第一步，这些试剂将在氧化还原反应中发挥与合成和催化中使用的经典过渡金属相同的作用。从基本和应用的角度来看，这种影响都是重大的。第2族元素通常被认为不能像过渡金属那样表现，这个项目将提供第一个可行的分子物种的实验证明，其中碱土金属的电子和化学性质将与过渡金属相似。由此产生的化合物将能够转化化学工业使用的普通气体（氢、氮、一氧化碳），从而为提高化学制造过程的可持续性开辟了新的合成可能性。

Our society relies on the chemical industry for the production of materials that assist and sustain our modern way of life. Manufacturing processes based on relatively simple chemical transformations are responsible for the production of drugs, pesticides, fuels and fertilisers, and it is quite common for these processes to be constructed around fundamental building blocks such as hydrogen, carbon monoxide and nitrogen. A typical example is the Fischer-Tropsch (FT) process, which is one of the most popular gas-to-liquid processes and is used for the production of long chain hydrocarbons from carbon monoxide and hydrogen. Its national strategic importance is demonstrated by the significant investments made by British companies (e.g. Johnson Matthey, BP, Velocys) in the development of new catalysts and FT reactors for the conversion of urban waste and biomass into renewable fuels, which is in line with the UK Government strategy to increase the number of FT plants and synthetic fuel supply by 2030. However, costs associated with these types of chemical manufacturing processes are usually very high, as they often rely on expensive and toxic transition metal reagents, and require very high temperatures and pressures.Earth abundant and non-toxic metals promise cheaper and more sustainable alternatives for chemical manufacturing processes. However, reagents based on these metals cannot break apart many of the small molecules used by these processes because of their lack of redox reactivity. Nonetheless, in recent years there have been many developments towards the generation of redox active Group 2 reagents, leading to the report of the first monovalent beryllium, magnesium and calcium species. This field is still in its infancy and these new species are yet to deliver transformations comparable to those of the traditional transition metal systems used by the chemical industry. New approaches must be devised to discover more sustainable alternatives and cheaper reagents that can mimic the performance of transition metal catalysts. This project will investigate the fundamental properties of the Alkaline Earth family (with the exception of beryllium and radium); these are Earth abundant and non-toxic metals, which could one day provide more sustainable alternatives for current materials employed by the chemical industry.In preliminary work we have demonstrated monovalent Alkaline Earth complexes can be stabilised with judicious and tailored molecular design. Our previous experimental and theoretical studies provide a blueprint that is transferrable to all the elements of the Group and will afford a new class of species in which the heavy Alkaline Earth metals possess transition metal-like electronic configuration, unlike previous examples of sub-valent Group 2 complexes. This is a first crucial step towards the preparation of Alkaline Earth reagents that will perform in redox reactivity in the same vein as classic transition metals employed in synthesis and catalysis. The repercussions of this are significant, both from the fundamental and applicative point of view. Group 2 elements are generally considered unable to behave like transition metals, and this project will provide the first experimental proof of viable molecular species where the electronic and chemical properties of the Alkaline Earth metals will parallel those of transition metals. The resulting compounds will be capable of transforming common gases used by the chemical industry (hydrogen, nitrogen, carbon monoxide), thus opening up new synthetic possibilities for improving the sustainability of chemical manufacturing processes.