Synthesis and reactivity of pincer type dinuclear complexes with metal-metal dative bond

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05812
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Inorganic chemistry
• Research Institution: Nara Women's University
• Principal Investigator: Nakajima Takayuki 奈良女子大学, 自然科学系, 准教授 (80322676)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 複核錯体 / 多核錯体 / 四座ホスフィン / 協同効果 / 銅 / イリジウム / ヒドリド / ギ酸

Outline of Final Research Achievements

We have utilized four linear tetradentate phosphine ligands with longer central methylene chains and different configurations at the inner phosphorous atoms, meso- and rac-Ph2PCH2P(Ph)(CH2)nP(Ph)CH2PPh2 (n = 2: dpmppe, 3:dpmppp, 4:dpmppb) to modulate the structures and reactivity of copper hydride species. These ligands gave a series of multinuclear copper hydride complexes with a variety of metal frameworks. Among these copper hydride complexes, only the copper hydride supported by meso-dpmppb showed reactivity toward CO2. Furthermore, the copper hydride was found to be a suitable catalyst for formic acid dehydrogenation into H2 and CO2. An unsymmetric dinuclear copper motif bridged by tetradentate phosphine ligands, was proposed as an active species to promote the decomposition of FA by virtue of synergistic effects of the Cu2 unit. The present system is the first distinguished catalytic dehydrogenation of FA by using cheap base metallic Cu complexes.

Free Research Field

有機金属化学

Academic Significance and Societal Importance of the Research Achievements

貴金属に代わり安価な卑金属を用いて同等の活性を持つ触媒反応の開発は元素戦略の観点から重要である。今回，四座ホスフィン配位子に安定に支持された銅2核中心が協同的に作業することで今までにない優れた触媒活性をもつギ酸の分解反応を見出したことは，今度の触媒反応開発に置いて重要な指針を与えるものである。また，これまで他のホスフィン配位子に比べ利用例が少ない四座ホスフィン配位子の有用性を実験的にも明らかにできたことは多座ホスフィン配位子の設計や合成，それを用いた錯体合成ならびに反応性など，錯体化学，有機金属化学，触媒化学の多方面に大きな影響を与える結果だと考えられる。