Tailoring of heteroleptic copper based photosensitizers and their photophysical characterization

杂配铜基光敏剂的定制及其光物理表征

• 批准号: 404309418
• 负责人: Dr. Michael Karnahl
• 金额: --
• 依托单位: Institut für Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/404309418?language=en
• 关键词: Tailoring; heteroleptic; copper; based; photosensitizers

The sufficient and environmentally friendly supply of energy is a major challenge in this century. A promising option is given by the increased use of solar energy, which requires the design of efficient, inexpensive and sustainable photosensitizers for light harvesting. In addition, a suitable photosensitizer should possess a strong absorption in the visible, long-lived excited states, a reversible electrochemical behavior and a high stability.So far molecular photosensitizers are most often based on rare and precious metals, like iridium or ruthenium, limiting their large-scale application. The usage of complexes based on earth-abundant metals in this approach is rather unexplored. To bring such non-noble systems into practice that has to be changed. In this respect photoactive copper(I) complexes possess a great potential.Therefore, the proposed project deals with the development of tailored heteroleptic Cu(I) photosensitizers and the detailed investigation of their (triplet) excited states as well as of their charge-transfer processes. For this purpose different design strategies, e.g. the exchange of classic diphosphine ligands by heterobidentate P^N ligands or a direct connection of the diimine and the diphosphine ligand, will be applied to enhance stability and absorptivity. Furthermore, additional electron storage moieties will be introduced, which allow to affect the redox properties specifically as well as the efficiency and time constant of the photoinduced electron transfer.The newly designed Cu(I) complexes will be systematically studied by steady-state as well as time-resolved transient absorption and emission spectroscopy to elucidate the underlying structure-property relationships and to understand the nature of the excited states. This should ultimately result in synthesis guidelines, e.g. in instructions to the right choice of the ligands, the type and position of substituents and the kind of electron storage. Within an iterative process these findings will be used straight away to further improve these Cu(I) photosensitizers.Moreover, these heteroleptic Cu(I) complexes will be applied for photon upconversion processes for the first time. In consequence, the capability of these compounds to transform photons of low energy into high energy photons, which allows to use a broader range of the light in subsequent reactions, will be clarified.All in all, by the combination of synthesis, structural and spectroscopic characterization as well as application of novel photoactive Cu(I) complexes this project will establish heteroleptic copper photosensitizers as a valuable class of substances for the priority program SPP 2102. This will finally contribute to an increased utilization and conversion of sunlight as a promising and clean energy source.

充足和环境友好的能源供应是本世纪的主要挑战。增加太阳能的使用是一个有希望的选择，这需要设计高效、廉价且可持续的光敏剂来进行光捕获。此外，合适的光敏剂还应具有可见光吸收强、激发态寿命长、电化学行为可逆和稳定性好等特点。目前，分子光敏剂大多以铱、钌等稀有贵金属为基础，限制了其大规模应用。在这种方法中使用基于地球上丰富的金属的络合物是相当未开发的。把这种非贵族的制度付诸实践，这是必须改变的。在这方面，光活性铜（I）配合物具有很大的潜力。因此，拟议的项目涉及定制的杂配型铜（I）光敏剂的开发和它们的（三重态）激发态以及它们的电荷转移过程的详细研究。为此目的，将应用不同的设计策略，例如通过异二齿P^N配体交换经典的二膦配体或直接连接二亚胺和二膦配体，以提高稳定性和吸收率。此外，将引入额外的电子存储部分，这些新设计的Cu（I）配合物将通过稳态和时间分辨瞬态吸收和发射光谱进行系统研究，以阐明其基本结构-性质关系和理解激发态的性质。这最终将产生合成指南，例如正确选择配体、取代基的类型和位置以及电子存储类型的说明。在一个迭代过程中，这些发现将直接用于进一步改进这些Cu（I）光敏剂。此外，这些杂配Cu（I）配合物将首次应用于光子上转换过程。因此，这些化合物将低能量光子转化为高能量光子的能力将被阐明，这允许在随后的反应中使用更宽范围的光。新型光活性Cu（I）结构、光谱表征及应用配合物，该项目将确立杂配铜光敏剂作为优先计划SPP 2102的一类有价值的物质。这最终将有助于增加太阳光作为一种有前途的清洁能源的利用和转化。