2026-07-13 分子科学研究所
図1. 4回対称性ユニットからnboトポロジーの3次元周期構造が組み上がる概念図。Brain Flakes®を使用。
＜関連情報＞
nboトポロジーをもつ結晶性3D共有結合性有機構造体 Crystalline 3D covalent organic frameworks with nbo topology
Soshi Hirota, Haruki Sugiyama, Nao Hirata, Sachiko Nakano, […] , and Yasutomo Segawa
Science Advances Published:10 Jul 2026
DOI:https://doi.org/10.1126/sciadv.aeg6230
Abstract
Three-dimensional covalent organic frameworks (3D COFs) are promising crystalline porous materials, but the elucidation of their structure remains challenging, particularly for those featuring spiroborate linkages. Herein, we report the synthesis of a 3D crystalline COF with nbo topology, constructed from a rigid square-planar monomer, tetracyclopentatetraphenylene (TCTP), and spiroborate linkages. Theoretical calculations revealed that the TCTP core has higher rigidity than phthalocyanine, effectively suppressing structural fluctuations during framework formation. The structure of the resulting TCTP-COF was successfully determined using microcrystal electron diffraction (MicroED), revealing a noninterpenetrated cubic framework. TCTP-COF exhibits high crystallinity, thermal stability up to 320°C, and permanent porosity with a Brunauer-Emmett-Teller surface area of 1360 square meters per gram. This work represents the structural determination of a spiroborate-linked 3D crystalline COF using MicroED methods, providing a design strategy for expanding the chemical space of highly ordered 3D COF architectures.
