The sequence of events during the photocyclisation of furylfulgides is not fully understood, and there is a significant disparity between ring closing timescales determined with the use of transient absorption (TA) spectroscopy [Siewertsen et al., Phys. Chem. Chem. Phys. 2011, 13, 3800.], and the timescale estimated on the basis of nonadiabatic molecular dynamics simulations [Kochman et al., Phys. Chem. Chem. Phys. 2022, 24, 18103.] With a view to resolving this issue, in the present study I report nonadiabatic molecular dynamics (NAMD) simulations of the photorelaxation process of a model furylfulgide with a bulky alkyl substituent at carbon atom C3. I employed a pattern recognition algorithm in order to automate the analysis of the simulated trajectories. According to the simulation results, the bulky alkyl group group causes a substantial increase in the photocyclisation quantum yield, but the timescale of ring closing is only marginally affected. I discuss the implications of these findings in light of the available spectroscopic data.

中文翻译：

---

非绝热分子动力学模拟揭示了呋喃酰酸光环化的时间尺度


呋喃酰精酸酐光环化过程中的事件顺序尚不完全清楚，并且使用瞬态吸收 (TA) 光谱确定的闭环时间尺度之间存在显着差异 [Siewertsen 等人，Phys.化学。化学。物理。 2011, 13, 3800.]，以及基于非绝热分子动力学模拟估计的时间尺度 [Kochman et al., Phys.化学。化学。物理。 2022, 24, 18103.] 为了解决这个问题，在本研究中，我报告了在碳原子 C3 上具有大烷基取代基的呋喃酰二酰亚胺模型的光弛豫过程的非绝热分子动力学 (NAMD) 模拟。我采用了模式识别算法来自动分析模拟轨迹。根据模拟结果，庞大的烷基基团导致光环化量子产率大幅增加，但闭环时间尺度仅受到轻微影响。我根据现有的光谱数据讨论了这些发现的含义。