基于铂(II)配合物的MOF结构：能量传递和电子转移及光催化应用

金属有机框架结构(MOF)是近二十年来兴起的一种新型孔材料，通常由含氧、氮原子的多齿有机结构单元与过渡金属离子自组装而成，在太阳能光化学转换中具有潜在的应用。本项目旨在利用光活性金属配合物构建MOF材料，研究MOF材料在光捕获后发生的能量传递和电子转移过程，抑制能量回传和电子逆向传递，获得长寿命电荷分离态，提高太阳光能转换效率。为此，我们将利用具有长寿命激发三重态的铂(II)-salphen配合物作为结构单元构建同核或者异核的MOF材料，通过超快光谱技术(包括飞秒瞬态吸收光谱和时间分辨发射光谱)研究MOF中铂(II)配合物的激发态性质，重点阐明这些光活性MOF材料吸收光以后在框架内的能量传递动力学以及MOF/溶液界面间发生的电子转移过程，利用这些MOF材料构建多相光催化体系，揭示MOF材料在太阳能转换中的影响因素，系统筛选基于MOF材料的最优光催化条件，实现水溶液中的光催化制氢。

Metal-organic frameworks (MOFs), a new class of crystalline materials built from well-defined molecular building blocks and metal or metal-cluster connecting points, have recently emerged as a versatile platform to integrate different molecular components to achieve artificial photosynthesis. This project gives importance to construct functional MOFs from photoactive metal complexes, to investigate intraframework energy transfer dynamics and MOF/solution interfacial electron transfer process. Further, project emphasis on to prevent harmful reduction of exciton lifetimes to achieve highly efficient conversion of solar to chemical energy. In detail, we propose to take square-planar platinum(II) salphen complexes as building blocks to construct robust MOFs, in view of their high stability, intense absorption in the visible region and long-lived excited states attributed to mixed metal-to-ligand charge transfer (MLCT) and ligand-to-ligand charge transfer (LLCT) transitions. Moreover, we are going to employ ultra-fast spectroscopic techniques including femtosecond transient absorption spectra and time-resolved emission spectra to investigate the dynamics of excited state deactivation. Also, we will establish heterogenous multi-component systems consisting of a sacrificial electron donor, a MOF photosensitizer and a cocatalyst to achieve photocatalytic hydrogen generation. Undertaking all these results, it would be feasible to elucidate the factors that influence the performance of MOF photocatalytic systems.