Syntheses of Doubly Oxido-Bridged Diruthenium Complexes as Models for the Biomimetic Oxidation Catalysts

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15301
• 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: Sophia University
• Principal Investigator: Misawa-Suzuki Tomoyo 上智大学, 理工学部, 准教授 (30824726)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 酸素二重架橋構造 / 二核錯体 / ルテニウム

Outline of Final Research Achievements

In this work, a model structure of some reaction sites of natural metalloenzymes, that have two iron centers doubly bridged by oxido ligands, has been developed using the Ru centers. The product is formally in the Ru(III)-Ru(IV) state and has terminal aqua /hydroxido ligands (OHn; n = 1, 2) on the doubly oxido-bridged diamond core. Through the studies on the purity and yield of the product, the number of synthetic steps or the reactivity of the starting material, a reaction of a singly oxido-bridged complex in basic aqueous solution has been chosen. Although the reactions of other complexes having bidentate bridging ligand such as carbonato on the doubly oxido-bridged core were attempted as well, the target complex was not obtained and, rather, some unexpected results were obtained in those reactions. Based on the redox potentials and pKa measured, the BDFE of the product is more than 90 kcal mol-1, indicating the potential as an oxidation reaction mediator.

Free Research Field

錯体化学

Academic Significance and Societal Importance of the Research Achievements

本研究では2つの鉄間を2つの酸素が架橋した金属酵素の活性点の模倣構造を、ルテニウム（Ru）により創製した。鉄錯体と比べて活性を低下（安定性を向上）させた「酸素二重架橋」Ru(III)-Ru(IV)二核錯体を構造モデルとして単離し、物性を評価した。Ru間を1つの酸素が架橋した錯体は水の酸化触媒として知られるが、「酸素二重架橋」の報告は少ない。鉄二核錯体に関する検討は数多い一方で、常温常圧で比較的安定なRu錯体による酸素二重架橋錯体の検討は学術的意義がある。温和な条件下の高効率な物質変換反応は急務であり、本研究の社会的意義は水や有機物の酸化反応過程の解明や分子設計に対して知見を与える点と考える。