The production of a radical cation-containing covalent organic framework (COF) has been accomplished by sequential in situ reactions, quaternization, and one-electron reduction of the 2,2'-bipyridine-based COFs. The acid-catalyzed COF formation enables the cis configuration of 2,2'-bipyridyl moieties in the structure, of which the stability arises from the eclipsed stacking of the two-dimensional layered structure. The postfunctionalization generates cyclic alkylated diquats as the sole products from the controlled quaternization. The reduction of diquat cations on the COF skeletons results in a large number of radical cations, which delocalize and uniaxially stack on top of one another by virtue of interlayered pi-electronic couplings. The absorption of the near-infrared (NIR) region exhibited by the cationic radical COF is remarkably high owing to the intercharge transfer across the pi-coupling interlayers. Also, the long-range array of extended and planar frameworks in such a COF leads to the extra stability of the radical cations against external stresses. The structure-enhanced performance of the COF material is witnessed with photothermal conversion efficiencies of as high as 63.8 and 55.2% when exposed to 808 and 1064 run lasers, respectively. Further PEG modification on such a COF allows photoacoustic imaging and photothermal therapy in vivo under NIR light illumination to be manifested.
Covalent Organic Frameworks toward Diverse Photocatalytic Aerobic Oxidations
作者:Shuyang Liu、Miao Tian、Xiubin Bu、Hua Tian、Xiaobo Yang
DOI:10.1002/chem.202100398
日期:2021.5.17
two‐dimensional covalentorganicframeworks (2D‐COFs) have become promising heterogenous photocatalysts in visible‐light‐drivenorganic transformations. Herein, a visible‐light‐driven selective aerobic oxidation of various small organic molecules by using 2D‐COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone‐based 2D‐COF‐1 on molecular
Amine-Linked Covalent Organic Frameworks as a Platform for Postsynthetic Structure Interconversion and Pore-Wall Modification
作者:Lars Grunenberg、Gökcen Savasci、Maxwell W. Terban、Viola Duppel、Igor Moudrakovski、Martin Etter、Robert E. Dinnebier、Christian Ochsenfeld、Bettina V. Lotsch
DOI:10.1021/jacs.0c12249
日期:2021.3.10
Covalentorganicframeworks have emerged as a powerful synthetic platform for installing and interconverting dedicated molecular functions on a crystalline polymeric backbone with atomic precision. Here, we present a novel strategy to directly access amine-linked covalentorganicframeworks, which serve as a scaffold enabling pore-wall modification and linkage-interconversion by new synthetic methods
three-dimensional covalent organic framework (3D COF) by installing functional anthracene moieties on its skeleton for 1O2 related applications. Attributed to its open networks, regular channels, and light skeletal density, the active anthracene sites in the 3D COF can be easily and fully accessed, hence affording superior performance compared with other materials such as 2-dimensional COFs and amorphous
单线态氧 ( 1 O 2 ) 的捕获和控制释放具有重要意义,但由于其非常短的寿命和高反应性而非常具有挑战性。为了应对这一挑战,我们通过在骨架上安装功能性蒽部分,合理设计和制造了高度结晶、坚固且多孔的三维共价有机骨架 (3D COF),用于1 O 2相关应用。由于其开放的网络、规则的通道和轻的骨架密度,3D COF 中的活性蒽位点可以轻松且完全地访问,因此与其他材料(如二维 COF 和无定形聚合物)相比具有优越的性能。值得注意的是,3D COF 显示了当前的历史新高所有报道的多孔材料中的1 O 2捕获率,通过各种表征技术和合理分析进行验证。此外,我们将 3D COF 平台用作防伪应用的刺激响应智能材料。该研究不仅为1 O 2 的捕获和释放提供了一个优秀的平台,而且扩展了COFs的应用范围。
Ionic Covalent Organic Frameworks: Design of a Charged Interface Aligned on 1D Channel Walls and Its Unusual Electrostatic Functions
作者:Ning Huang、Ping Wang、Matthew A. Addicoat、Thomas Heine、Donglin Jiang
DOI:10.1002/anie.201611542
日期:2017.4.24
neutral porous materials. Here, we report the construction of ionic crystalline porous COFs with positively charged walls that enable the creation of well aligned yet spatially confined ionicinterface. The unconventional reversed AA‐stacking mode alternately orientates the cationic centers to both sides of the walls; the ionicinterface endows COFs with unusual electrostatic functions. Because all
The construction of a new class of covalent TTF lattice by integrating TTF units into two‐dimensional covalentorganicframeworks (2D COFs) is reported. We explored a general strategy based on the C2+C2 topological diagram and applied to the synthesis of microporous and mesoporous TTF COFs. Structural resolutions revealed that both COFs consist of layered lattices with periodic TTF columns and tetragonal
据报道,通过将TTF单元整合到二维共价有机骨架(2D COF)中,可以构造一类新型的共价TTF晶格。我们探索了基于C 2 + C 2的一般策略拓扑图,并应用于微孔和中孔TTF COF的合成。结构解析表明,两个COF均由具有周期性TTF柱和四方开放纳米通道的分层晶格组成。TTF色谱柱为高效率的空穴传输提供了预先设计的途径,占了COF的HOMO和LUMO的水平,并且具有氧化还原活性,可以形成有机盐,其电导率提高了几个数量级。另一方面,TTF单元之间的连接基在通过2D薄片构象和层间距离的扰动确定载流子迁移率和电导率方面起着至关重要的作用。这些结果为设计一种新型TTF材料提供了一条途径,该材料具有稳定且可预先设计的晶格结构,可用于功能性探索。