Development of Solid-State Molecular Machine Based On Pseudo-rotaxane Structure

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K14691
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Hokkaido University
• Principal Investigator: Takahashi Kiyonori 北海道大学, 電子科学研究所, 助教 (90812595)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: 超分子化学 / 分子運動 / 固相分子機械 / 擬ロタキサン / リラクサー / 強誘電体 / 分子結晶

Outline of Final Research Achievements

pseudorotaxane-type supramolecular cations were prepared as counter cation of [Ni(dmit)2] salts and their single crystal structures were investigated in correlation with their dielectric responses.
Supramolecular cation consisted of dibenzo[24]crown-8 and dialkylammonium with carbon chain lengths of 1, 3, and 4 could be prepared. In the salts with carbon chain lengths of 3 and 4, dialkylammonium was disordered at two sites, suggesting molecular motion in the crystalline state. The salt with bis(chloroethyl)ammonium showed a dielectric response similar to that of relaxor ferroelectrics.

Free Research Field

超分子科学

Academic Significance and Societal Importance of the Research Achievements

リラクサー強誘電体は、結晶内でのナノ分極秩序に基づく。一次元鎖状に配列する擬ロタキサン型超分子カチオン集合体は、嵩高いdibenzo[24]crown-8 によって隣接鎖間の相互作用が無視できるほど小さいことが想定できる。すなわち、単一次元鎖の配列に基づく新奇なリラクサー強誘電性が実現している可能性がある。分子レベルでの低次元秩序に基づく強誘電性システムは類例に乏しく、新しいリラクサー強誘電体としてのポテンシャルを示すことができた。