1415238-25-3Relevant articles and documents
Perylene-based covalent organic frameworks for acid vapor sensing
Ascherl, Laura,Evans, Emrys W.,Gorman, Jeffrey,Orsborne, Sarah,Bessinger, Derya,Bein, Thomas,Friend, Richard H.,Auras, Florian
, p. 15693 - 15699 (2019)
Traditionally, the properties and functions of covalent organic frameworks (COFs) are defined by their constituting building blocks, while the chemical bonds that connect the individual subunits have not attracted much attention as functional components of the final material. We have developed a new series of dual-pore perylene-based COFs and demonstrated that their imine bonds can be protonated reversibly, causing significant protonation-induced color shifts toward the near-infrared, while the structure and crystallinity of the frameworks are fully retained. Thin films of these COFs are highly sensitive colorimetric acid vapor sensors with a detection limit as low as 35 μg L-1 and a response range of at least 4 orders of magnitude. Since the acidochromism in our COFs is a cooperative phenomenon based on electronically coupled imines, the COFs can be used to determine simultaneously the concentration and protonation strength of nonaqueous acid solutions, in which pH electrodes are not applicable, and to distinguish between different acids. Including the imine bonds as function-determining constituents of the framework provides an additional handle for constructing multifunctional COFs and extending the range of their possible applications.
COVALENT ORGANIC FRAMEWORKS AND APPLICATIONS AS PHOTOCATALYSTS
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, (2021/05/21)
Described herein are covalent organic frameworks. The covalent organic frameworks have unique structural and physical properties, which lends them to be versatile in a number of different applications and uses. In one aspect, the covalent organic frameworks are composed of a plurality of fused aromatic groups and electron-deficient chromophores. The covalent organic frameworks are useful as photocatalysts in a number of different applications.
Exploitation of two-dimensional conjugated covalent organic frameworks based on tetraphenylethylene with bicarbazole and pyrene units and applications in perovskite solar cells
Chueh, Chu-Chen,EL-Mahdy, Ahmed F. M.,Kuo, Shiao-Wei,Lüder, Johann,Lee, Chia-Chen,Li, Zhen,Mohamed, Mohamed Gamal,Yu, Ming-Hsuan,Zhu, Zonglong
, p. 11448 - 11459 (2020/06/17)
In this work, two-dimensional conjugated covalent organic frameworks (2D-COF) based on a building block of tetraphenylethylene are successfully developed. Bicarbazole and pyrene moieties are respectively coupled with 4,4′,4′′,4′′′-(ethane-1,1,2,2-tetrayl)tetranilino (ETTA)via[4 + 4] solvothermal condensation conditions of 3,3′,6,6′-tetraformyl-9,9′-bicarbazole (Car-4CHO) and 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) to affordCar-ETTAandTFPPy-ETTACOFs. According to thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), and N2adsorption and desorption measurements, bothCar-ETTAandTFPPy-ETTACOFs exhibit excellent thermal stability, highly crystalline structure, and high specific surface area, respectively. These findings are supported by force field andab initiocalculations. Furthermore, successful applications of these COFs in perovskite solar cells (PVSCs) are demonstrated owing to their well-conjugated properties and π-π interactions. While serving as interlayers in the devices, these COFs could effectively promote the interfacial charge dynamic to further optimize the resulting performance. Besides, certain interaction between COFs and perovskite also leads to an improved morphology and crystallinity of the perovskite layer, presenting defect passivation capability. As a result, we show that the performance of the COF-modified PVSC could be improved from 17.40 to 19.80%.
