Strudwick Benjamin H, O'Bryen Christopher, Sanders Hans J, Woutersen Sander, Buma Wybren Jan
Molecular Photonics Group, Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
Phys Chem Chem Phys. 2019 Jun 5;21(22):11689-11696. doi: 10.1039/c9cp01906e.
Time-resolved vibrational spectroscopy studies are reported on the photoinduced structural dynamics of 2,2-diphenyl-2H-chromene, a prototypical photochromic compound that undergoes ring opening upon UV radiation. The transient IR absorption measurements in combination with (TD-)DFT calculations have been used to understand in detail the life cycle of such compounds. Excited-state decay and ring opening was found to occur on an ultrafast time scale. Three species have been identified in the time-resolved IR spectra with two short-lived species (on a picosecond timescale) and a final long-lived species that remains after the measurable ns delay range. These species have been assigned to various open isomers using quantum chemical calculations of equilibrium structures and force fields. From the experiments and calculations key conclusions can be drawn on previously suggested models for the photocycle of such compounds, as well as on possible ways to controllably influence the performance of these compounds.
报道了时间分辨振动光谱研究，该研究针对2,2-二苯基-2H-色烯的光诱导结构动力学，2,2-二苯基-2H-色烯是一种典型的光致变色化合物，在紫外线辐射下会发生开环反应。瞬态红外吸收测量结合（TD-）DFT计算已被用于详细了解此类化合物的生命周期。发现激发态衰变和开环在超快时间尺度上发生。在时间分辨红外光谱中鉴定出三种物质，其中两种是短寿命物质（在皮秒时间尺度上），还有一种是在可测量的纳秒延迟范围之后仍然存在的最终长寿命物质。利用平衡结构和力场的量子化学计算，将这些物质分配到各种开环异构体中。从实验和计算中，可以得出关于此类化合物光循环的先前提出的模型的关键结论，以及可控地影响这些化合物性能的可能方法。
