Isolated 2-hydroxypyrene and its dimer: a frequency- and time-resolved spectroscopic study
Isolated 2-hydroxypyrene and its dimer: a frequency- and time-resolved spectroscopic study
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DOI：
10.1039/d0nj02391d
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发表时间：
2020-06
影响因子：
3.3
通讯作者：
Hans-Christian Schmitt;I. Fischer;L. Ji;Julia Merz;T. Marder;Joscha Hoche;M. Röhr;R. Mitrić
中科院分区：
文献类型：
--
作者：
Hans-Christian Schmitt;I. Fischer;L. Ji;Julia Merz;T. Marder;Joscha Hoche;M. Röhr;R. Mitrić
我们研究了孤立的2-羟基芘和它的二聚体在气相中的时间和频率分辨的光电离与皮秒的时间分辨率。实验支持的模拟，包括广泛的构象搜索的基础上的机器学习ANI-1ccx神经网络的潜力结合自动结构分类使用的数据聚类算法。本文报道了S_1 <$S_0和S_2 <$S_0跃迁的振动分辨谱，在TDDFT水平上与模拟谱符合得很好。正如所预期的从参与过渡的分子轨道，红移的过渡是更明显的S1状态相比，未取代的芘。虽然在S1态观察到ns寿命，但在S2态的起源处，寿命降低到3 ps或更小，表明两个态之间存在强相互作用。对于二聚体，一个轻微的V形结构进行了计算，和分子间的相互作用主要是分散，而不是氢键。最高的振子强度计算的过渡到S4状态，其中在4 ps内失活到一个较低的激发态。
We investigated isolated 2-hydroxypyrene and its dimer in the gas phase by time- and frequency-resolved photoionisation with picosecond time-resolution. The experiments are supported by simulations that include an extensive conformational search based on the machine learning ANI-1ccx neural network potential combined with automatic structure classification using a data clustering algorithm. Vibrationally resolved spectra of the S1 ← S0 and S2 ← S0 transitions are reported which are in very good agreement with the simulated spectra at the TDDFT level. As expected from the molecular orbitals involved in the transitions, the red-shifts of the transitions are more pronounced for the S1 state compared to those of unsubstituted pyrene. While a ns-lifetime is observed for the S1 state, the lifetime decreases to 3 ps or less for the origin of the S2 state, indicating a strong interaction between the two states. For the dimer, a slightly V-shaped structure was computed, and intermolecular interactions are dominated by dispersion rather than hydrogen-bonding. The highest oscillator strength was computed for the transition to the S4 state, which deactivates within 4 ps to a lower-lying excited state.