Journal of the American Chemical Society p. 12570 - 12581 (2019)
Update date:2022-08-11
Topics:
Sick, Torben
Rotter, Julian M.
Reuter, Stephan
Kandambeth, Sharath
Bach, Nicolai N.
D?blinger, Markus
Merz, Julia
Clark, Timothy
Marder, Todd B.
Bein, Thomas
Medina, Dana D.
Two-dimensional covalent organic frameworks (2D COFs) attract great interest owing to their well-defined pore structure, thermal stability, high surface area, and permanent porosity. In combination with a tunable chemical pore environment, COFs are intriguing candidates for molecular sieving based on selective host-guest interactions. Herein, we report on 2D COF structures capable of reversibly switching between a highly correlated crystalline, porous and a poorly correlated, nonporous state by exposure to external stimuli. To identify COF structures with such dynamic response, we systematically studied the structural properties of a family of two-dimensional imine COFs comprising tris(4-aminophenyl)benzene (TAPB) and a variety of dialdehyde linear building blocks including terephthalaldehyde (TA) and dialdehydes of thienothiophene (TT), benzodithiophene (BDT), dimethoxybenzodithiophene (BDT-OMe), diethoxybenzodithiophene (BDT-OEt), dipropoxybenzodithiophene (BDT-OPr), and pyrene (Pyrene-2,7). TAPB-COFs consisting of linear building blocks with enlarged π-systems or alkoxy functionalities showed significant stability toward exposure to external stimuli such as solvents or solvent vapors. In contrast, TAPB-COFs containing unsubstituted linear building blocks instantly responded to exposure to these external stimuli by a drastic reduction in COF layer correlation, long-range order, and porosity. To reverse the process we developed an activation procedure in supercritical carbon dioxide (scCO2) as a highly efficient means to revert fragile nonporous and amorphous COF polymers into highly crystalline and open porous frameworks. Strikingly, the framework structure of TAPB-COFs responds dynamically to such chemical stimuli, demonstrating that their porosity and crystallinity can be reversibly controlled by alternating steps of solvent stimuli and scCO2 activation.
View Morewebsite:http://www.amadischem.com
Contact:86-571-89925085
Address:Watts Cosine.No.166.Xiangmao Road.
ZHEJIANG JIANYE CHEMICAL CO.,LTD.
Contact:86-571-64149273,64149234
Address:No. 48, Fuxi Road, Meicheng Town
Contact:+86-021-50792271
Address:Building 24A, 300 Chuantu Road, Chuansha, Pudong new area, Shanghai, China, 201202
NingBO Hong Xiang Biochem.Co.Ltd
website:http://www.hxbiochem.com
Contact:0574-66003444
Address:Ning Bo Bei Lun
Xi'an yuanfar international trade company
website:https://www.yuanfarchemical.com
Contact:86-029-88745613 ext 828
Address:Floor19th ,B Building, Oak Block,No.36 South Fenghui Road, Dev. Zone of High-Tech Ind.,Xi’an, China
Doi:10.1016/j.tet.2005.06.083
(2005)Doi:10.1021/acs.orglett.7b04022
(2018)Doi:10.1002/hlca.19390220188
(1939)Doi:10.1016/0040-6031(95)02675-4
(1996)Doi:10.1021/jo00370a031
(1986)Doi:10.1039/c39810000775
(1981)