Development of tools for mechanistic understanding and optimisation of photochemical reactions

我的项目将集中在光催化反应的发展和机理的理解（在批或流）使用在线，紧凑的质谱（CMS）和流动NMR光谱作为分析工具。首先，我将研究1，1-双（吡啶）盐的烷基化作为一种新型的酰基阴离子当量，使用水合铵添加剂作为内标。这种新的（但非光催化）合成转化将作为一个简单的平台，在其上开发我们的CMS监测能力，使用蠕动泵和采样阀循环基于烧瓶的反应混合物进行在线分析。一旦这种监测技术得到优化，我们的1，1-bis作为一种新的转化方法，我将开始使用CMS监测来研究光催化反应。（吡啶鎓）盐作为试剂，但将尝试在Minisci中产生用于芳烃C-H官能化的α-吡啶碳中心自由基，紧凑型CMS现在将用于优化在连续流中进行的反应，从而自动化protocols将用于筛选催化剂和条件。博士项目的后期部分将使用CMS和流动NMR来探测我们实验室开发的光催化反应的机制。特别是，我将尝试使用底物/反应物的离子标记来获得定量动力学数据，并研究各种内在和外在参数对光催化反应速率的影响（例如，催化剂、光波长/强度、温度）。还将研究催化剂失活过程及其对反应效率的影响（例如，对于作为催化剂的4CzIPN）。最后，我将尝试使用一种来自Mettler-Tolledo的专门的取样探针来进行非均相光反应的动力学分析，例如该小组最近开发的以MeCN为溶剂的伯胺的α-C-H噻唑基化反应。

My project will focus on the development and mechanistic understanding of photocatalytic reactions (in batch or flow)using on-line, compact mass spectrometry (CMS) and flow NMR spectroscopy as analytic tools.At the outset, I will study the alkylation of 1,1-bis(pyridinium) salts as a new type of acyl anion equivalent, using aquaternary ammonium additive as an internal standard. This novel (but non-photocatalytic) synthetic transformationwill serve as a simple platform on which to develop our CMS monitoring capabilities, using a peristaltic pump andsampling valve to circulate a flask-based reaction mixture for on-line analysis. Once this monitoring technique hasbeen optimised, and our 1,1-bis(pyridinium) alkylation method published as a novel transformation, I will begin toinvestigate photocatalytic reactions using CMS monitoring.The novel photocatalytic process that I will target will again be based on 1,1-bis(pyridinium) salts as reagents, but willattempt to generate alpha-pyridium carbon-centred radicals for arene C-H functionalisation in a Minisci-type process.Compact CMS will now be used to optimise reactions conducted in continuous flow, whereby automated protocolswill be used to screen catalysts and conditions.The later part of the PhD project will use CMS and flow NMR to probe the mechanisms of photocatalytic reactionsdeveloped in our lab. In particular, I will attempt to use ion-tagging of a substrate/reactant to obtain quantitativekinetic data, and to study the effect of various intrinsic and extrinsic parameters on the photocatalytic reaction rate(e.g., catalyst, light wavelength/intensity, temperature). Catalyst deactivation processes, and their influence onreaction efficiency, will also be studied (e.g., for 4CzIPN as catalyst). Finally, I will attempt to use a specialisedsampling probe from Mettler-Tolledo to carry out kinetic analysis of heterogeneous photoreactions, such as thegroup's recently developed alpha-C-H thiazoylation of primary a mines in MeCN as the solvent.