Development of Pillar-Type Molecular Wire Based on Molecular Junction Using Au-pi Bindings

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K14602
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 32020:Functional solid state chemistry-related
• Research Institution: Osaka University
• Principal Investigator: Yokoyama Soichi 大阪大学, 産業科学研究所, 助教 (40811211)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: 分子ワイヤ / 単一分子素子 / オリゴチオフェン / オリゴフェニレン / 分子エレクトロニクス / 単分子接合 / 単分子電気伝導度

Outline of Final Research Achievements

In this study, the relation between molecular orbitals and single molecular conductance was investigated by using pillar-like molecular wire, which can control the distribution of the molecular orbitals for wire and anchor units, toward development of molecular electronics showing excellent conductance. Pillar-like molecular wires consisting of π-conjugated oligophenylene or oligothiophene as wire unit and triazatriangulene (TATA) skeletons as anchor units, which were orthogonally linked, were designed and synthesized to understand the factor that the distribution of molecular orbitals on wire or anchor units affects on molecular conductance. It was found that the pillar-like molecular wires exhibited high conductance in the tunneling region due to the strong electronic coupling of the TATA anchor units to the gold electrode.

Free Research Field

構造有機化学

Academic Significance and Societal Importance of the Research Achievements

本研究では、金-π軌道接合が接触抵抗を減少させることでコンダクタンスが向上すること、ワイヤ部では電荷がホッピングするサイトのエネルギー準位を揃えることが長距離電荷輸送時におけるコンダクタンス減衰の抑制につながるといった学術的知見を得ることができた。これら知見は、有機分子特有の低コンダクタンスという課題点を克服できる可能性を持つことから、次世代の有機デバイス素子材料を開発する上での有用な設計指針になることが期待できる。