Unlocking Photoswitchable Main-group Catalysis Using Azophosphines

催化剂是使化学反应更有效的物质，对化学工业至关重要；事实上，90%的商业化学品在其生产过程中至少涉及一个催化步骤。这些催化剂很大一部分依赖于贵金属（如钯、铂、金和铑）；据预测，到2026年，全球贵金属催化剂市场规模将达到267.3亿美元。然而，贵金属也有一些缺点，主要是因为它们很珍贵，也就是说，它们很稀有，而且非常昂贵。开采这些低丰度金属的经济成本巨大，开采和加工矿石的环境成本不断增加，导致化石燃料的使用和二氧化碳排放增加。由于迫切需要更好地管理地球的资源，我们迫切需要找到更可持续的替代品来支持未来的化学工业。这项提议的研究将推动使用由廉价和丰富的元素制成的催化剂，如氮、磷和硼，在被称为受挫刘易斯对（FLPs）的系统中。之前已经开发的大多数FLP催化剂都是对空气敏感的，在使用它们时需要专门的技术，这限制了有机化学家对它们的吸收，并在工业上得到更广泛的应用。这项提案的研究将集中在设计一种新的分子家族上，这种分子家族可以在光照下改变形状，因此可以作为催化的开关，具有“开”或“关”的状态。这些含有磷和氮作为关键元素的新分子将用于在正常条件下（“关闭”状态）稳定且无活性的FLP中，但可以用光激活成为功能性无金属催化剂（“打开”状态）。台架稳定的前体（预催化剂）将使FLP催化获得更广泛的学术和工业受众。该项目代表了英国的优先领域，与EPSRC的物理科学和未来制造业的主题非常一致。这也符合联合国可持续发展目标，特别是目标9：“工业、创新和基础设施”。

Catalysts are substances that make chemical reactions more efficient and are crucial to the chemical industry; in fact, 90% of commercial chemicals involve at least one catalytic step in their production. A high proportion of these catalysts rely on precious metals (e.g., palladium, platinum, gold and rhodium); it is forecast that the global precious metal catalysts market will reach $26.73 billion by 2026. And yet precious metals have several disadvantages, predominantly arising from the fact that they are precious, i.e., they are scarce and very expensive. There is a huge economic cost associated with mining these low-abundance metals, and an increasing environmental cost with extracting and processing the ore that is leading to an increase in fossil fuel usage and carbon dioxide emissions. With a pressing need to better manage the planet's resources, we urgently need to find more sustainable alternatives to support the chemical industry of the future.The proposed research will drive forward the use of catalysts made from cheap and abundant elements, such as nitrogen, phosphorus, and boron, in systems known as Frustrated Lewis Pairs (FLPs). Most of the previous FLP catalysts that have been explored are air-sensitive, and require specialist techniques when using them, which has limited their uptake by organic chemists and more widely in industry. The research in this proposal will focus on the design of a new family of molecules that can change shape when light is shone on them, and can therefore act as switches with "on" or "off" states for catalysis. These new molecules, containing phosphorus and nitrogen as the key elements, will be used within an FLP that is stable and inactive under normal conditions ("off" state), but can be activated with light to become a functional metal-free catalyst ("on" state). The bench-stable precursors (pre-catalysts) will make FLP catalysis accessible to a broader academic and industrial audience.The project represents a priority area for the UK, and aligns strongly with the EPSRC's themes of Physical Sciences and Manufacturing the Future. It also tallies with the United Nations (UN) Sustainable Development Goals, specifically Goal 9: 'Industry, Innovation and Infrastructure.'