Laser-induced Photochemistry in Continuous Flow Reactors

光化学是上个世纪一些最有趣的化学进展背后的研究领域。这种化学方法能够高度选择性地激活分子，然后驱动分子反应并进行特定的化学合成。光驱动的化学反应也是植物通过光合作用利用太阳能的基础。此外，半导体中的选择性太阳光吸收可以允许进行宽范围的通常高度非选择性的光催化批量化学反应，例如氧化和还原反应。尽管我们了解光化学，但该主题未能对精细化工和制造业产生重大影响。在某种程度上，这与调整/停止光化学反应的困难有关，这样它们就不会产生不需要的副反应，也与将实验室光化学反应放大到工业规模过程的困难有关。在这项研究中，我们将研究在精细化学品和纳米材料的高价值制造中利用可调光化学的路线，为工业规模工艺的可扩展性提供了令人信服的证据。此外，我们将利用光的特殊性质来实现特定的目标，例如通过使用光的偏振来增加产品的特异性。所有反应将在连续流反应环境中进行，这将允许我们调整入射激光的路径长度和吸收截面、停留时间、温度、压力、混合湍流、浓度等。作为一个高级阶段，我们将能够使用该装置来使用超临界二氧化碳进行反应，（高压和中等温度），其是一种清洁的溶剂，其将允许与反应性气体（例如氢气）的显著更高的可溶解性。有针对性地使用光来选择性地激活连续流动过程中的溶剂或特定分子的独特组合（从一开始就具有高度可扩展性的潜力）以前从未被证明过，并且包含可持续的化学原理。在该提案的时间范围内，我们将展示精细有机复合物的概念验证光导向制造，包括手性分子（具有内置“handedness”的分子）和表面功能化无机纳米材料，这些都是将我们的概念转化为工业所需的。我们拥有一支平衡的团队，包括有机化学和激发态光-物质相互作用，无机合成和化学工程方面的专业知识。特别是，这包括最近在中试规模工厂（公斤/小时）上首次演示超临界连续流处理，随着手性光化学的最新进展，这使得我们的提议具有非凡的及时性。我们的工作对工业界和学术界都将产生重大影响。英国政府商业、创新和技能部（BIS）最近的一份报告称，“英国化学品行业是全球第七大生产商，年销售额约为560亿英镑，占英国所有制造业的12%”。[1]其目的是发展这一部门，使其能够继续在国际上竞争。为此，报告指出，需要沿着新技术的创新和知识转让，以及获得技能和培训的机会。该项目直接满足了这些需求。特别是通过在英国建立概念验证，并通过与英国行业的合作，我们将提供一个平台，使他们能够继续在国际上竞争。[1]商业、创新和技能部2010年12月发布了《先进制造业增长审查框架》报告。URN 10/1297。

Photochemistry is an area of research behind some of the most interesting advances in chemistry over the last century. This approach to chemistry enables the highly selective activation of molecules which can then be driven to react and undergo specific chemical syntheses. Photo-driven chemical reactions are also the basis upon which plants can harness the suns energy via photosynthesis. Furthermore, selective solar light absorption in semiconductors can allow a wide range of often highly unselective photocatalytic batch chemistries to be conducted such as oxidation and reduction reactions. Despite our knowledge of photochemistry, the subject has failed to have a significant impact on the fine chemical and manufacturing industries. In part, this is related to the difficulty in tuning/stopping photochemical reactions so that they do not give unwanted side reactions and also the difficulties associated with scaling-up laboratory photochemical reactions into industrial scale processes.In this study, we will investigate routes for utilising tuneable photochemistry in the high value manufacture of fine chemicals and nanomaterials, providing compelling evidence of scalability towards industrial scale processes. Furthermore, we will harness special properties of light to achieve specific goals, for example by using the polarisation of light to add product specificity. All reactions will be conducted in a continuous flow reaction environment which will allow us to tune path lengths and absorption cross-sections for incident lasers, residence times, temperatures, pressures, turbulence of mixing, concentrations etc. Furthermore, as an advanced stage we will be able to use the apparatus for carrying out reactions using supercritical carbon dioxide (high pressure and moderate temperature) which is a clean solvent that will allow substantially higher miscibility's with reactive gases such as hydrogen. The unique combination of the targeted use of light to selectively activate either a solvent or specific molecules within a continuous flow process (which has the potential to be highly scalable from the outset) has never been demonstrated before and encompasses sustainable chemistry principles. Within the timescale of this proposal we will demonstrate proof-of-concept light-directed manufacture of fine organic complexes, including chiral molecules (molecules with a built-in 'handedness'), and surface functionalised inorganic nanomaterials, required to translate our concept to industry. We have a balanced team that includes expertise in organic chemistry and excited state light-mater interactions, inorganic synthesis and chemical engineering. In particular, this includes the recent first demonstration of supercritical continuous flow processing on a pilot-scale plant (kg/hour) which, with recent advances in chiral photochemistry, makes our proposal of exceptional timeliness. The impact of our work will be highly significant to both industry and academia. A recent Government Department for Business, Innovation & Skills (BIS) review reported that 'The UK Chemicals sector is the seventh largest producer globally with annual sales of around £56bn, representing 12% of all UK manufacturing'.[1] The aim is to grow this sector and enable it to continue to compete internationally. To do this the report states that innovation and knowledge transfer of new technologies is required along with access to skills and training. This project directly addresses these needs. Specifically by establishing the proof-of-concept within the UK and through engagement with UK-based industry we will provide a platform to enable them to continue to compete internationally.[1] Department for Business, Innovation and Skills report 'Growth Review Framework for Advanced Manufacturing' December 2010. URN 10/1297.