Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States.
Department of Chemistry, Stanford University, Stanford, California 94305, United States.
J Am Chem Soc. 2021 Dec 8;143(48):20015-20021. doi: 10.1021/jacs.1c06648. Epub 2021 Nov 11.
Detailed mechanistic understanding of multistep chemical reactions triggered by internal conversion via a conical intersection is a challenging task that emphasizes limitations in theoretical and experimental techniques. We present a discovery-based, hypothesis-free computational approach based on first-principles molecular dynamics to discover and refine the switching mechanism of donor-acceptor Stenhouse adducts (DASAs). We simulate the photochemical experiment , following the "hot" ground state dynamics for 10 ps after photoexcitation. Using state-of-the-art graphical processing units-enabled electronic structure calculations we performed in total ∼2 ns of nonadiabatic molecular dynamics discovering (a) critical intermediates that are involved in the open-to-closed transformation, (b) several competing pathways which lower the overall switching yield, and (c) key elements for future design strategies. Our dynamics describe the natural evolution of both the nuclear and electronic degrees of freedom that govern the interconversion between DASA ground-state intermediates, exposing significant elements for future design strategies of molecular switches.
详细了解通过锥形交叉内部转换引发的多步化学反应的机理是一项具有挑战性的任务，这凸显了理论和实验技术的局限性。我们提出了一种基于第一性原理分子动力学的基于发现的、无假设的计算方法，用于发现和完善给体-受体 Stenhouse 加合物（DASAs）的开关机制。我们模拟光化学反应，在光激发后跟随“热”基态动力学 10 ps。我们使用最先进的图形处理单元启用的电子结构计算总共进行了约 2 ns 的非绝热分子动力学，发现了（a）参与开环到闭环转化的关键中间体，（b）几个降低整体开关产率的竞争途径，以及（c）未来设计策略的关键要素。我们的动力学描述了控制 DASA 基态中间体之间转换的核和电子自由度的自然演化，为分子开关的未来设计策略揭示了重要元素。
