Zhu Yingting, Huang Yichao, Li Qi, Zang Dejin, Gu Jing, Tang Yajie, Wei Yongge
Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry , Tsinghua University , Beijing 100084 , China.
Department of Chemistry and Biochemistry , San Diego State University , 5500 Campanile Drive , San Diego , California 92182-1030 , United States.
Inorg Chem. 2020 Feb 17;59(4):2575-2583. doi: 10.1021/acs.inorgchem.9b03540. Epub 2020 Feb 6.
Polyoxometalates (POMs)-porphyrin hybrids can serve as multifunctional materials with fascinating photocatalytic and photovoltaic properties. However, most previous POM-porphyrin hybrids are synthesized relied on electrostatic interactions to form ion pairs, which is not stable enough and subject to leaching and poor electronic communication. To our knowledge, no specific crystalline structure of direct covalently tris-functionalized POM-porphyrin hybrids has been identified. Herein, we discover an unprecedented polyoxometalates (POMs)-based photoresponsive cluster, {VO[ZnCHNO]} (denoted as V-Zn-2Por), which can be synthesized by covalently grafting two tris-functionalized Zn-porphyrin ligands onto Lindqvist-type hexavanadate cluster using decavanadates (TBA)[HVO] (denoted as V10, TBA = tetrabutylammonium cation) as precursor. Additionally, using tetraphenyl phosphonium as counterion, for the first time, a high-quality single crystal structure of the hybrid hexavanadate-porphyrin molecule is uncovered. Interestingly, the fluorescence emission spectra show that the fluorescence intensity of the organic-inorganic hybrid is partly quenched compared to pristine porphyrins, indicating possible energy/electron transfer between POMs cluster and porphyrin under light irradiation. Their UV-vis diffuse reflectance spectra show an extended absorption in the visible-light range. Finally, the as-prepared photoresponsive hexavanadate-porphyrin molecule is proved to exhibit effective photocatalytic activity toward removal of rhodamine B (an organic dye) under visible-light illumination.
多金属氧酸盐（POMs）-卟啉杂化物可作为具有迷人光催化和光伏特性的多功能材料。然而，大多数先前的POM-卟啉杂化物是依靠静电相互作用合成以形成离子对，这种方式不够稳定，容易发生浸出且电子通讯性差。据我们所知，尚未确定直接共价三官能化POM-卟啉杂化物的特定晶体结构。在此，我们发现了一种前所未有的基于多金属氧酸盐（POMs）的光响应性簇合物{VO[ZnCHNO]}（记为V-Zn-2Por），它可以通过使用十钒酸盐（TBA）[HVO]（记为V10，TBA = 四丁基铵阳离子）作为前体，将两个三官能化的锌卟啉配体共价接枝到Lindqvist型六钒酸盐簇合物上而合成。此外，首次使用四苯基鏻作为抗衡离子，揭示了杂化六钒酸盐-卟啉分子的高质量单晶结构。有趣的是，荧光发射光谱表明，与原始卟啉相比，有机-无机杂化物的荧光强度部分猝灭，这表明在光照下POMs簇合物和卟啉之间可能存在能量/电子转移。它们的紫外-可见漫反射光谱显示在可见光范围内有扩展吸收。最后，所制备的光响应性六钒酸盐-卟啉分子被证明在可见光照射下对去除罗丹明B（一种有机染料）表现出有效的光催化活性。
