Organic triplet-triplet annihilation upconversion (TTA-UC) materials have considerable promise in areas as broad as biology, solar energy harvesting, and photocatalysis. However, the development of highly efficient near-infrared (NIR) light activatable TTA-UC systems remains extremely challenging. In this work, we report on a method of systematically tailoring an annihilator to attain such outstanding systems. By chemical modifications of a commonly used perylene annihilator, we constructed a family of perylene derivatives that have simultaneously tailored triplet excited state energy (T1) and singlet excited state energy (S1), two key annihilator factors to determine TTA-UC performance. Via this method, we were able to tune the TTA-UC system from an endothermic type to an exothermic one, thus significantly elevating the upconversion performance of NIR light activatable TTA upconversion systems. In conjunction with the photosensitizer PdTNP (10 μM), the upconversion efficiency using the optimal annihilator (100 μM) identified in this study was measured to be 14.1% under the low-power density of NIR light (100 mW/cm2, 720 nm). Furthermore, using such a low concentration of perylene derivative, we demonstrated that the optimal TTA-UC pair developed in our study can act as a highly effective light wavelength up-shifter to enable NIR light to drive a photoredox catalysis that otherwise requires visible light. We found that such an NIR driven method is highly effective and can even surpass directly visible light driven photoredox catalysis. This method is important for photoredox catalysis as NIR light can penetrate much deeper in colored photoredox catalysis reaction solutions, especially when done in a large-scale manner. Furthermore, this TTA-UC mediated photoredox catalysis reaction is found to be outdoor sunlight operable. Thus, our study provides a solution to enhance NIR activatable organic upconversion and set the stage for a wide array of applications that have previously been limited by the suboptimal efficiency of the existing TTA upconversion materials.

中文翻译：

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用于光氧化还原催化的高效近红外激活三重态-三重态湮灭上转换

有机三重态-三重态湮灭上转换 (TTA-UC) 材料在生物学、太阳能收集和光催化等广泛领域具有相当大的前景。然而，开发高效的近红外 (NIR) 光可激活 TTA-UC 系统仍然极具挑战性。在这项工作中，我们报告了一种系统地定制歼灭器以获得如此出色的系统的方法。通过对常用苝湮灭剂的化学修饰，我们构建了一系列苝衍生物，它们同时定制了三重激发态能量 (T1) 和单重激发态能量 (S1)，这两个决定 TTA-UC 性能的关键湮灭因子。通过这种方法，我们能够将 TTA-UC 系统从吸热型调整为放热型，从而显着提升 NIR 光可激活 TTA 上转换系统的上转换性能。结合光敏剂 PdTNP (10 μM)，在低功率密度 NIR 光 (100 mW/cm2, 720 nm) 下，使用本研究中确定的最佳湮灭剂 (100 μM) 测得的上转换效率为 14.1% . 此外，使用如此低浓度的苝衍生物，我们证明了我们研究中开发的最佳 TTA-UC 对可以作为高效的光波长上移器，使 NIR 光能够驱动光氧化还原催化，否则需要可见光。我们发现这种 NIR 驱动的方法非常有效，甚至可以超越直接可见光驱动的光氧化还原催化。这种方法对于光氧化还原催化很重要，因为 NIR 光可以在有色光氧化还原催化反应溶液中穿透得更深，尤其是在以大规模方式进行时。此外，发现这种 TTA-UC 介导的光氧化还原催化反应可在室外阳光下进行。因此，我们的研究提供了一种增强 NIR 可激活有机上转换的解决方案，并为之前因现有 TTA 上转换材料的次优效率而受到限制的广泛应用奠定了基础。