Three-dimensional Salphen-based Covalent–Organic Frameworks as Catalytic Antioxidants

Abstract

The development of three-dimensional (3D) functionalized covalent organic frameworks (COFs) is of critical importance for expanding their potential applications. However, the introduction of functional groups in 3D COFs remains largely unexplored. Herein we report the first example of 3D Salphenbased COFs (3D-Salphen-COFs) and their metal-containing counterparts (3D-M-Salphen-COFs), the later being further used as catalytic antioxidants. These Salphen-based COFs exhibit high crystallinity and specific surface area in addition to excel lent chemical stability. Furthermore, the Cu(II)-Salphen COF displayed high activity in the removal of superoxide radicals. This study not only presents a new pathway to construct 3D functionalized COFs, but also promotes their applications in biology and medicine.

Salen‐Based Conjugated Microporous Polymers for Efficient Oxygen Evolution Reaction

“…[22,23] Thus,w es peculated that salen-containing frameworks and polymers may display good electrocatalytic OER performance, because salen-CMPs combine the rigid conjugated porous structure of CMPs and the intrinsic electrocatalytic activity of the salen moiety. [24][25][26][27][28][29][30] In this work we have demonstrated the ability of salen-containingp olymers to act as electrocatalysts for the first time. The electrochemical test results showed that the catalyst salen-CMP-Fe-3 showed the highest OER activity.W hen loaded onto glass carbon electrodes, the prepared salen-CMP-Fe-3 electrodes demonstratedas mall Tafel slope of 63 mV dec À1 and an overpotentialo f2 38 mV at 10 mA cm À2 in 0.1 m KOH.…”

Metal Salen- and Salphen-Containing Organic Polymers: Synthesis and Applications

“…In 2019, Fang and coworkers reacted halogenated orthophenylene diamines with Mastalerz's tetraphenylmethanebased tetrakis-salicylaldehyde under solvothermal conditions and obtained the highly crystalline COFs JUC-508 (Hal ¼ F) and JUC-509 (Hal ¼ Cl) (Scheme 13). 124 These networks retained their crystallinity after complexation with Mn 2þ , Cu 2þ , and Eu 3þ ions. PXRD analyses in combination with modeling revealed for all COFs noninterpenetrated networks of a dia topology.…”

“…PXRD analyses in combination with modeling revealed for all COFs noninterpenetrated networks of a dia topology. 124 When an extended tetraphenylmethane core with one more phenyl group 122 or a siliconcentered analogue was used, sevenfold interpenetrated salphen COFs resulted, again with the dia topology (Scheme 14). 125 In this case, an in-situ metalation upon condensation in addition to the postmetalation of presynthesized COFs gave networks with high degrees of crystallinity.…”

“…126 The obtained materials showed gel-like behavior and have Scheme 13 Syntheses and structural motifs of Mastalerz's MaSOF-1 and -2, as well as Fang's JUC-508, JUC-509, and the corresponding metalated networks. 123,124 Scheme 14 Cui's COF-1, COF-2, COF-2-Zn, and COF-2-Zn. 124 Scheme 15 Synthesis of a chiral Mn-salen imine gel.…”

“…123,124 Scheme 14 Cui's COF-1, COF-2, COF-2-Zn, and COF-2-Zn. 124 Scheme 15 Synthesis of a chiral Mn-salen imine gel. Inset: photograph of Mn-salen imine gel (0.02 mol/L in DMSO).…”