Ultrafine Spatial Modulation of Diazapyrene-Based Two-Dimensional Conjugated Covalent Organic Frameworks.

Autor: Li Z; Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan., Tsuneyuki T; Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan., Paitandi RP; Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan., Nakazato T; Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan., Odawara M; Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan., Tsutsui Y; Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan., Tanaka T; Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan., Miyake Y; Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan., Shinokubo H; Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan., Takagi M; Graduate School of Nanobio Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, Kanagawa 236-0027, Japan., Shimazaki T; Graduate School of Nanobio Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, Kanagawa 236-0027, Japan., Tachikawa M; Graduate School of Nanobio Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, Kanagawa 236-0027, Japan., Suzuki K; Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan., Kaji H; Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan., Ghosh S; Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan., Seki S; Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
Jazyk: angličtina
Zdroj: Journal of the American Chemical Society [J Am Chem Soc] 2024 Aug 21; Vol. 146 (33), pp. 23497-23507. Date of Electronic Publication: 2024 Aug 08.
DOI: 10.1021/jacs.4c07091
Abstrakt: Tailormade bottom-up synthesis of covalent organic frameworks (COFs) from various functional building blocks offer not only tunable topology and pore size but also multidimensional properties. High crystallinity is one of the prerequisites for their structures and associated physicochemical properties. Among different π-conjugated motifs for constructing COFs, pyrene-based tetragonal structures are effective in achieving highly ordered and crystalline states. In the present research, we demonstrated that the substitution of pyrene with 2,7-diazapyrene produces nearly "flat" structures of two-dimensional (2D) COF layers by controlling the torsional angle of linker molecules. Featuring finite pore diameters and excellent thermodynamic stability of ∼500 °C, ordered face-to-face (slipped AA) stacking arrangements were produced. Extended electrical conjugation spanning 2D frames with modest optical bandgaps ( E g ) of ∼2.1 eV shows the planar character of diazapyrene-based COFs. The stacking of the conjugated 2D frames with small E g values is also beneficial for the formation of highly stable conducting pathways in the crystalline state, which was confirmed by the results of the microwave conductivity measurements. Nitrogen centers in diazapyrene units also play a key role as the active sites for proton transfer, and the maximum proton conductivity of σ = 10 -2 S cm -1 was achieved along the cocontinuous nanopore structures surrounded by the active sites. Results show that tetragonal COFs based on diazapyrene can be used as a highly crystalline two-dimensional material with special electrical and proton-conducting capabilities.
Databáze: MEDLINE
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