Circularly polarized triplet exciton emission from chiral MOF-immobilized and -organized copper(I) complexes

手性光活性化合物的激发态具有圆偏振发光(CPL)特性，在对映体选择性传感器、数据存储、(3D)OLED或量子密码学中的超快开关等领域具有广阔的应用前景。目前的CPL化合物大多是基于荧光态和稀土元素的，这两种化合物都不是光电子学应用的最佳选择。然而，设计具有高量子产额和高辐射速率常数的磷光CPL材料的探索要少得多，因为形式上自旋禁止的T1发射需要与具有足够的电子跃迁偶极矩到基态的Sn态耦合，而它们中的每一个可能具有不同的磁跃迁偶极矩m的取向(导致整体m的部分抵消)，这是强CPL所必需的。因此，预测CP磷光甚至CP-TADF(热激活延迟荧光)的程度是困难的，已知的少数例子表明CP相对较弱，金属有机骨架(MOF)是具有先进光物理性质的新型材料的靶向设计平台，如激光、多光子吸收和客体、温度或压力依赖的发光。将光活性分子发光团固定在刚性的晶体配位网络中可以显著提高它们的发光参数(发光寿命、量子产率等)。由于提高了光稳定性，抑制了非辐射失活，以及发光体在3D空间中的定向对准和排列。在这个合作项目中，我们的目标是结合我们的专业知识构建包含手性高效有机金属铜(I)发光体的多孔MOF，这些发光体可以从T1态或通过TADF发射，排列在三维晶格中。为此，我们将遵循非常具体的设计策略，在单晶、粉末和薄膜中获得有益的CPL性能，并将这些新材料应用于CP-PhOLED。

Excited states of chiral photoactive compounds are of great interest because they can exhibit circularly polarized luminescence (CPL) with a yet to fully explore potential in enantioselective sensors, data storage, (3D-)OLEDs, or ultrafast switching in quantum cryptographical applications. The majority of current CPL compounds is based on fluorescent states and lanthanides, both of which are not the optimal choice for optoelectronic applications. However, the design of phosphorescent CPL materials with high quantum yield and high radiative rate constants is much less explored as the formally spin-forbidden T1 emission requires coupling with Sn states of sufficient electronic transition dipole moment to the ground state, while each of them may have a different orientation of the magnetic transition dipole moment m (leading to partial cancellation of the overall m) that is necessary for strong CPL. Therefore, prediction of the extent of CP phosphorescence or even CP-TADF (thermally activated delayed fluorescence) is difficult, and the few examples known show relatively weak CPL.Metal-organic frameworks (MOFs) are promising platforms for the targeted design of novel materials with advanced photophysical properties, such as lasing, multi-photon absorption and guest, temperature or pressure dependent luminescence. The immobilization of photoactive molecular luminophores in a rigid crystalline coordination network can significantly improve their luminescence parameters (luminescence lifetime, quantum yield, etc.) due to increased photo-stability, a suppression of non-radiative deactivation as well as a targeted alignment and arrangement of the luminophores in 3D space. Within this collaborative project, we aim to combine our expertise for the construction of porous MOFs containing chiral highly-efficient organometallic Cu(I) luminophores, which can emit from their T1 state or via TADF, arranged in a three-dimensional lattice. For this, we will follow a very specific design strategy to obtain beneficial CPL properties in single crystals, powders and films, and employ these new materials in CP-PhOLEDs.