Room temperature phosphorescence from organic materials has attracted an increasing attention in the recent years due to their potential application in various advancing technologies, notably in bioimaging and displays. In this context, heavy atoms such as halogen ones revealed useful tools to enhance the spin‐orbit coupling (SOC) of molecular organic phosphors. However, the effect of halogen at the supramolecular level remains less understood, especially in the field of molecular crystals where additional factors can impact the phosphorescence emission. Here, we investigate external effect of halogens on the phosphorescence of chiral phthalimides molecular crystals. The results show that changing the nature of the halogen atom onto the phthalimide core leads to an evolution of the photophysical properties of the materials which does not necessarily follow the classical trend imposed by the expected internal heavy atom effect. Beyond this aspect, we showed that the halogen atom has a profound impact on the packing between the chromophores at the supramolecular level which is of paramount importance towards the optical properties (PLQY and lifetimes) of the different phosphors examined.

中文翻译：

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卤素对显示室温磷光的手性邻苯二甲酰亚胺发射体超分子组织的影响


近年来，有机材料的室温磷光由于其在各种先进技术（特别是生物成像和显示）中的潜在应用而引起了越来越多的关注。在这种情况下，卤素等重原子揭示了增强分子有机磷光体自旋轨道耦合（SOC）的有用工具。然而，卤素在超分子水平上的影响仍然知之甚少，特别是在分子晶体领域，其中其他因素可能影响磷光发射。在这里，我们研究了卤素对手性邻苯二甲酰亚胺分子晶体磷光的外部影响。结果表明，改变邻苯二甲酰亚胺核上卤素原子的性质会导致材料光物理性质的演变，这不一定遵循预期的内部重原子效应所施加的经典趋势。除此之外，我们还发现卤素原子在超分子水平上对发色团之间的堆积具有深远的影响，这对于所检查的不同荧光粉的光学性能（PLQY 和寿命）至关重要。