Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, ul. Zwirki i Wigury 101, 02-096 Warsaw, Poland.
Molecules. 2019 Mar 20;24(6):1107. doi: 10.3390/molecules24061107.
The crystal structure of 1-(pyren-1-yl)but-2-yn-1-one ( 1 a , a polynuclear aromatic hydrocarbon displaying enhanced luminescence in the solid state, has been re-determined at several pressures ranging from atmospheric up to 3 GPa using a Diamond Anvil Cell (DAC). These experiments were augmented by periodic DFT calculations at pressures up to 4.4 GPa. UV-Vis fluorescence of 1 a at non-ambient pressures has also been investigated. The crystal structure consists of infinite π -stacks of anti-parallel 1 a molecules with discernible dimers, which may exemplify aggregates formed by pyrene derivatives in solution and thin films, and is predominantly stabilized by dispersion. The average inter-planar distance between individual molecules within π -stacks decreases with pressure in the investigated range. This results in piezochromic properties of 1 a : a red-shift of sample color, as well as a bathochromic shift of fluorescence with pressure (by ca. 100 nm at 3.5 GPa). Two-component fluorescence spectra support the hypothesis that at least two types of excimers are involved in the electronic excitation processes in crystalline 1 a .
1-(芘-1-基)-2-丁炔-1-酮（1a）的晶体结构已在从大气压到 3 GPa 的几个压力范围内使用金刚石压腔（DAC）重新确定，该多环芳烃在固态下具有增强的发光性。这些实验通过高达 4.4 GPa 的周期性 DFT 计算得到了补充。1a 在非环境压力下的紫外-可见荧光也得到了研究。晶体结构由反平行 1a 分子的无限π -堆叠组成，具有可识别的二聚体，这可能例证了溶液和薄膜中芘衍生物形成的聚集体，主要由色散稳定。在所研究的范围内，π -堆叠中各个分子之间的平均层间距离随压力而减小。这导致了 1a 的压致变色性质：样品颜色的红移，以及荧光随压力的红移（在 3.5 GPa 时约为 100nm）。双组分荧光光谱支持了这样的假设，即在结晶 1a 中，电子激发过程至少涉及两种类型的激基缔合物。
