Comprehensive SummaryThe problem of molecular diffusion in the soup of chemical reactions attracts mounting interest across fields ranging from chemistry to biophysics to material science. Chemical reactions involve bond breakup and formation, whose time scale is typically on the orders of fs to ps, while molecular diffusion occurs at time scales of μs to ms. The two processes are often considered orthogonal, given the vastly different scales. The serial results show that the enzyme's diffusion is enhanced in a substrate‐dependent manner, which was further extended to small molecule reaction systems, challenging this classical paradigm. However, the results from different groups using different techniques do not quantitatively agree, and a general mechanism is yet to be understood. We summarize experimental studies on diffusion problems and seek to reconcile the interpretation with understanding the limits of measurement tools and the chemical nature of reaction systems. Understanding molecular diffusion in chemical reactions will provide fresh thoughts in designing chemical systems such as molecular machines that harvest work at the nanoscale in a controllable manner.

中文翻译：

---

化学反应系统中增强扩散问题的测量比较

综合总结化学反应汤中的分子扩散问题引起了从化学到生物物理学再到材料科学等各个领域越来越多的兴趣。化学反应涉及键的断裂和形成，其时间尺度通常为fs至ps量级，而分子扩散发生在μs至ms的时间尺度上。鉴于规模截然不同，这两个过程通常被认为是正交的。系列结果表明酶的扩散以底物依赖性方式增强，并进一步扩展到小分子反应系统，挑战了这种经典范式。然而，不同小组使用不同技术的结果在数量上并不一致，并且一般机制尚待了解。我们总结了扩散问题的实验研究，并寻求将解释与理解测量工具的局限性和反应系统的化学性质相协调。了解化学反应中的分子扩散将为设计化学系统（例如以可控方式在纳米级收获功的分子机器）提供新的思路。