2次元共役高分子を巻き上げる ~世界最高レベルのプロトン伝導性を示すチューブ状COFの合成に成功~

ad

2025-04-17 名古屋大学

2次元共役高分子を巻き上げる ~世界最高レベルのプロトン伝導性を示すチューブ状COFの合成に成功~

名古屋大学と複数の研究機関の共同研究により、共有結合性有機構造体(COF)を巻き上げてナノチューブ状に形成し、世界最高レベルのプロトン伝導性を示す材料の合成に成功しました。ジアザピレンを構成単位とする2次元COFシートが液液界面で自発的に巻き上がり、1次元チューブ構造を形成します。この構造体は、プロトン伝導性がσ=1.98 S/cmと非常に高く、エネルギー変換デバイスへの応用が期待されます。また、超音波照射によりチューブ構造がシートに戻る可逆性も確認されました。

<関連情報>

2次元COFシートを巻き上げて1次元電子伝導性・プロトン伝導性ナノチューブ構造へ Rolling two-dimensional covalent organic framework (COF) sheets into one-dimensional electronic and proton-conductive nanotubes

Zhuowei Li, Rajendra Prasad Paitandi, Yusuke Tsutsui, +17 , and Shu Seki
Proceedings of National Academy of Science  Published:April 16, 2025
DOI:https://doi.org/10.1073/pnas.2424314122

Significance

Tunable/designable topology and porous network make π-conjugated COFs a counterpart of graphenes and have been expected as a new class of organic optoelectronic materials. Electron transport in these materials is the critical parameter to optimize the above properties/functionalities. Nanoscale morphology of π-conjugated COFs one of the critical parameters that governs the electrical conductivity, like interconvertible carbon allotropes of 2D graphene and 1D carbon nanotubes (CNTs), that exhibits distinct electronic properties. Similarly, transforming 2D π-conjugated COF sheets into 1D structures is demonstrated herein, allowing us to control the “flow” of electrons and protons. 1D tubular conjugated COFs are thus an ace to place conjugated COFs on the level challenging to graphenes in their electronic properties.

Abstract

Mimicking the interconvertible carbon allotropes of 2-dimensional (2D) graphene and 1-dimensional (1D) carbon nanotubes (CNTs), herein we report the in situ transformation of 2D π-conjugated covalent organic frameworks (COFs) sheet into 1D nanotubular structures via self-assembly the sheets at solvent interfaces. The facile “roll-sheets” self-assembly resulted in coaxial nanotubes with uniform cross-sectional diameter, which was realized for diazapyrene-based COFs but not for the corresponding pyrene COF, although both possess similar chemical structures. Upon replacing the carbon atoms at 2,7-positions of pyrene with nitrogen, contrasting optical and electronic properties were realized, reflecting the rolled structure of the conjugated 2D sheets. The nanotubes exhibited concerted electronic- and proton-conducting nature with stable conducting pathways at ambient conditions. The nitrogen centers act simultaneously as the site for charge carrier doping and proton acceptors, as evidenced by the high photo- and electrical conductivity, as well as the record proton conductivity (σ = 1.98 S cm−1) results. The present diazapyrene-based 1D nanotubular COF serves as a unique materials platform with electronic conduction in the wall and proton conduction in the core, respectively.

0500化学一般
ad
ad
Follow
ad
タイトルとURLをコピーしました