Regioselective assembling of metal complexes for the creation of new artificial photosynthetic systems

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K14237
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 34010:Inorganic/coordination chemistry-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Wakizaka Masanori 東京工業大学, 科学技術創成研究院, 特任助教 (00786840)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: デンドリマー錯体

Outline of Final Research Achievements

In this study, metal chlorides of the early 4d/5d-transition-metals, i.e., Zr(IV), Nb(V), Mo(V), Hf(IV), Ta(V), and W(VI), were stoichiometrically introduced into a tetraphenylmethane-core dendritic-phenylazomethine generation 4 dendrimer in the presence of an optimal amount of organic ligands such as pyridine and 3-chloropyridine. The coordinative interactions between the metal chlorides and the imines in the dendrimers indicated a positive correlation for the Lewis acidity of the metals. Moreover, it was clearly demonstrated for the first time that heterometallic assemblies of defined composition contain four kinds of early 4d/5d-transition-metals, such as Ta(V), Nb(V), Mo(V), and Zr(IV), which was confirmed by UV-vis titration, XPS, and HAADF-STEM/EDS measurements. The results of this study should provide access to new routes to produce nanomaterials composed of heterometallic early 4d/5d-transition metals.

Free Research Field

ナノ材料科学

Academic Significance and Societal Importance of the Research Achievements

二酸化炭素排出量の削減は国際的に非常に重大な差し迫ったテーマである。また、我が国は化石燃料を海外からの輸入に強く依存しているため、限られた炭素資源の有効活用も考えなければいけない。これらの問題を同時に解決するのが人工光合成や二酸化炭素固定と呼ばれる技術である。本研究はデンドリマー内に複数の前周期4d/5d金属を集積することに初めて成功した。特に、二酸化炭素活性化サイトとして、柔軟なレドックス特性を示したモリブデンが有望であることが分かった。