Gao Yu, Guan Wei, Yan Likai
Institute of Functional Material Chemistry, National & Local United Engineering Lab for Power Battery, Key Laboratory of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry , Northeast Normal University , Changchun 130024 , P. R. China.
J Phys Chem A. 2018 Sep 20;122(37):7491-7496. doi: 10.1021/acs.jpca.8b06876. Epub 2018 Sep 10.
A series of Keggin-type polyoxometalate (POM)-based organic-inorganic complexes (systems 2-8) were designed with different π-linkers on the basis of the molybdate-pyrene hybrid (system 1). UV-vis spectra and charge transfer (CT) parameters of designed systems were systematically analyzed by density functional theory (DFT) and time-dependent DFT (TD-DFT). The results indicate that the absorption spectra are red-shifted and the absorption intensities are enhanced with increasing number of phenylacetylene π-oligomers and introducing benzodifuranone between benzene and ethyne. However, the π-linkers near POMs are "dissolved" in the total system and the excitation occurs in a local region with increasing π-linkers. Systems 3 and 6 possess the maximum CT distance and CT charge among systems 1-5 and systems 6-8, respectively, resulting from the balance point between effectiveness of structures and delocalization. The absorption spectra of systems 6-8 obviously red-shift in comparison to systems 1-5. The present study is a further step toward the optimal absorption and CT properties.
基于钼酸盐-芘杂化物（体系1），设计了一系列具有不同π-连接体的基于Keggin型多金属氧酸盐（POM）的有机-无机配合物（体系2 - 8）。通过密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）对设计体系的紫外-可见光谱和电荷转移（CT）参数进行了系统分析。结果表明，随着苯乙炔π-低聚物数量的增加以及在苯和乙炔之间引入苯并二呋喃酮，吸收光谱发生红移且吸收强度增强。然而，POMs附近的π-连接体在整个体系中“溶解”，并且随着π-连接体数量的增加，激发发生在局部区域。体系3和体系6分别在体系1 - 5和体系6 - 8中具有最大的CT距离和CT电荷，这是结构有效性和离域之间平衡点的结果。与体系1 - 5相比，体系6 - 8的吸收光谱明显红移。本研究朝着优化吸收和CT性能又迈进了一步。
