Fluorescence lifetime imaging microscopy (FLIM) is an emerging tool to characterize ongoing chemical reactions in synthetic chemistry and catalysis. Initially applied to biological systems, FLIM now reveals spatially resolved chemical reaction species and system-wide physiochemical changes that accompany ongoing reactions. FLIM combines the advantage of environmental sensitivity with high signal sensitivity (as sensitive as single molecules) and has the key ability to operate under synthetic conditions (e.g., high concentrations of reagents, in organic solvents, under ambient temperature and pressure, in opaque mixtures, and in multiphasic systems). Chemical reactions inherently induce changes in the reaction medium, neighboring compounds, surface compositions, and/or the bonding structure of the compounds involved, resulting in environmental changes. The FLIM methods recently developed harness and interpret these changes in ways that lead to characterizing compounds and enhancing mechanistic understanding. Here, current advantages and limitations of FLIM method are considered, common factors influencing fluorescence lifetime in chemical systems are discussed in a tutorial format, and seven research case studies are strategically analyzed—chosen to highlight how FLIM provided complementary information to understand chemical reaction mechanisms, intermediates, product distributions, partitioning, roles of reagents, and catalyst behaviors. These data and insights obtained from FLIM assist the rational design and optimization of synthetic and catalytic methods.

中文翻译：

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荧光寿命成像显微镜 (FLIM) 作为了解化学反应和催化的工具


荧光寿命成像显微镜 (FLIM) 是一种新兴工具，用于表征合成化学和催化中正在进行的化学反应。 FLIM 最初应用于生物系统，现在揭示了空间解析的化学反应物种和伴随正在进行的反应的系统范围的物理化学变化。 FLIM结合了环境敏感性和高信号敏感性（如单分子一样灵敏）的优点，并具有在合成条件下（例如高浓度试剂、有机溶剂中、环境温度和压力下、不透明混合物中、以及在多相系统中）。化学反应本质上会引起反应介质、邻近化合物、表面组成和/或所涉及化合物的键合结构的变化，从而导致环境变化。最近开发的 FLIM 方法利用并解释了这些变化，从而能够表征化合物并增强对机理的理解。在这里，考虑了 FLIM 方法当前的优点和局限性，以教程的形式讨论了影响化学系统中荧光寿命的常见因素，并战略性地分析了七个研究案例研究 - 选择突出 FLIM 如何提供补充信息来理解化学反应机制，中间体、产物分布、分配、试剂的作用和催化剂行为。从 FLIM 获得的这些数据和见解有助于合成和催化方法的合理设计和优化。