Successive construction of cucurbit[8]uril-based covalent organic frameworks from a supramolecular organic framework through photochemical reactions in water  

作　　者：Yawen Li Chaochao Yan Qingfang Li Liping Cao 

机构地区：[1]College of Chemistry and Materials Science,Northwest University,Xi’an 710069,China [2]Frontier Institute of Science and Technology,Xi’an Jiaotong University,Xi’an,710054,China

出　　处：《Science China Chemistry》2022年第7期1279-1285,共7页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (22122108, 21971208);the Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province of China (2021JC-37);the Fok Ying Tong Education Foundation (171010)。

摘　　要：Functional framework materials have been developed for many applications including adsorption, asymmetric catalysis, sensing,drug delivery, optical device, and so on. Here, we report the successive construction of two cucurbit[8]uril-based covalent organic frameworks(COFs) including tetraphenylethene-based COF(COF-1) and phenanthrene-based COF(COF-2) from a two-dimensional(2D) periodic cucurbit[8]uril-based supramolecular organic framework(SOF-1) as the prearranged structure via the intermolecular photocycloaddition of the coumarin units and the intramolecular photocyclization of the tetraphenylethene(TPE) units under ultraviolet(UV) irradiation(365 nm) in water. In this case, oxygen(O_(2)) plays an important role in the photocyclization of the TPE units into the phenanthrene units in the transform process from SOF-1 or COF-1 to COF-2. As the TPE units further form phenanthrenes after UV-irradiation, COF-2 exhibits aggregation-caused quenching effect and weak green emission, while COF-1 displays a strong yellow emission due to the aggregation-induced emission. Besides, the adaptive chirality of cationic COF-1 as a biomolecular sensor can be efficiently induced by chiral anionic biomolecules including adenosine-5′-triphosphate(ATP) and adenosine-5′-diphosphate(ADP) to exhibit sensitive negative circular dichroism responses in water. This supramolecular approach to construct COF from SOF via photochemical reactions may open a new opportunity for the construction and application of the water-soluble COFs with well structural controllability, unique photophysical properties,and favorable biocompatibility.

关 键 词：covalent organic framework supramolecular organic framework CUCURBIT[8]URIL photochemical reaction adaptive chirality 

分 类 号：O641.3[理学—物理化学]