Developing open-shell molecular structures of high-energy and novel spin-functional unit by use of elementary particle muons

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02685
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 32020:Functional solid state chemistry-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Ito Shigekazu 東京工業大学, 物質理工学院, 准教授 (00312538)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: ラジカル / 素粒子 / ミュオン / ミュオニウム / 有機合成化学 / 複素環

Outline of Final Research Achievements

In this project, we attempted generating unusual paramagnetic species by utilizing muoniums which were formed from muon and electron. Muons are produced by proton accelerators, and the muonium can provide novel molecular structures that cannot be prepared by usual chemical methods. At first, we confirmed addition of muonium to the phosphorus heterocycles of singlet biradicals suggesting that the regioselectivity would remarkably correlate with the electronic properties and the crystal structures. Next, we characterized the regioselective muoniation to the phosphorus analog of anthracene together with the unprecedented quasi-stable conjugated system which was induced by the muon isotope effect. In addition, we succeeded in observing an imidoyl radical by using muonium first time, and produced particular paramagnetic pai-conjugated structures from the heavier carbonyl compounds.

Free Research Field

有機化学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果は、有機合成化学とミュオンをうまく組み合わせることによって前例のない開殻分子構造を創り出せることを明確に証明した。ミュオンの高エネルギー状態は、通常では不安定で生成できない開殻共役系分子構造などを与えるだけでなく、分子の物性に強く相関した情報も得られる。空間的にも時間的にも分子創成の可能性を飛躍的に向上させることが可能となり、前衛的な物質科学の展開がこれから大いに期待される。