Molecular Electronics of Open-Shell Molecule Based on Spin-Dependent Photoexcited State Dynamics

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02788
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Kyoto University
• Principal Investigator: MATSUDA Kenji 京都大学, 工学研究科, 教授 (80262145)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 分子エレクトロニクス / 開殻分子 / 励起状態

Outline of Final Research Achievements

Bis(imino nitroxide) bridged by a diarylethene annulated isomer was synthesized, and the exchange interaction between the two radicals was determined by the simulation of the ESR spectrum. The exchange interaction was found to be as large as that of the closed-ring isomer, suggesting that the annulated isomer can be used as a highly-conductive molecular wire. Electron tunneling efficiency of armchair graphene nanoribbons was evaluated by calculating decay constant of the exchange interaction. It was found that the electron tunneling efficiency is significantly large in the case of N = 3n-1. Single-molecular conductances were compared between molecular wires with and without radical substituent by STM apparent height measurement. Statistical analysis of the STM images revealed that the radical-substituted wire has larger conductance than the non-radical-substituted reference.

Free Research Field

物理有機化学

Academic Significance and Societal Importance of the Research Achievements

本研究では、ESRの線形から見積もられる交換相互作用の見積もり、計算によって得られた交換相互作用の減衰定数、STM測定高さによる分子コンダクタンスの見積もり、などの手法により、優れた電子輸送特性を有する分子骨格はどのようなものであるかを示すことができた。今後より高度な機能をもつ分子回路の設計に重要な知見が得られたと言える。