Flexibility Matters: Cooperative Active Sites in Covalent Organic Framework and Threaded Ionic Polymer

Journal of the American Chemical Society, Год журнала: 2016, Номер 138(48), С. 15790 - 15796

Опубликована: Ноя. 17, 2016

The combination of two or more reactive centers working in concert on a substrate to facilitate the reaction is now considered state art catalysis, yet there still remains tremendous challenge. Few heterogeneous systems this sort have been exploited, as active sites spatially separated within rigid framework are usually difficult cooperate. It shown that roadblock can be surpassed. underlying principle strategy presented here integration catalytic components with excellent flexibility and porous catalysts, demonstrated by placement linear ionic polymers close proximity surface Lewis acid anchored walls covalent organic (COF). Using cycloaddition epoxides CO2 model reaction, dramatic activity improvements achieved for composite catalysts relation individual component. Furthermore, they also clearly outperform benchmark formed molecular organocatalysts while affording additional recyclability. extraordinary enriched concentration catalytically moieties concerted thus leading superior performance. This work therefore uncovers an entirely new designing bifunctional double-activation behavior opens avenue design multicapable mimic biocatalysis.

Язык: Английский

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Facile transformation of imine covalent organic frameworks into ultrastable crystalline porous aromatic frameworks

Nature Communications, Год журнала: 2018, Номер 9(1)

Опубликована: Июль 25, 2018

The growing interest in two-dimensional imine-based covalent organic frameworks (COFs) is inspired by their crystalline porous structures and the potential for extensive π-electron delocalization. intrinsic reversibility strong polarization of imine linkages, however, leads to insufficient chemical stability optoelectronic properties. Developing COFs with improved robustness π-delocalization highly desirable but remains an unsettled challenge. Here we report a facile strategy that transforms imine-linked into ultrastable aromatic kinetically fixing reversible linkage via aza-Diels-Alder cycloaddition reaction. as-formed, quinoline-linked not only retain crystallinity porosity, also display dramatically enhanced over COF precursors, rendering them among most robust up-to-date can withstand acidic, basic redox environment. Owing diversity reaction structural tunability COFs, pores be readily engineered realize pre-designed surface functionality.

Язык: Английский

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Porous Polymers as Multifunctional Material Platforms toward Task‐Specific Applications

Advanced Materials, Год журнала: 2018, Номер 31(4)

Опубликована: Окт. 22, 2018

Exploring advanced porous materials is of critical importance in the development science and technology. Porous polymers, being famous for their all-organic components, tailored pore structures, adjustable chemical have attracted an increasing level research interest a large number applications, including gas adsorption/storage, separation, catalysis, environmental remediation, energy, optoelectronics, health. Recent years witnessed tremendous breakthroughs these fields thanks to unique structures versatile skeletons polymers. Here, recent milestones diverse applications polymers are presented, with emphasis on structural requirements or parameters that dominate properties functionalities. The Review covers following applications: i) adsorption, ii) water treatment, iii) iv) heterogeneous v) electrochemical energy storage, vi) precursors carbons, vii) other (e.g., intelligent temperature control textiles, sensing, proton conduction, biomedicine, actuators). key each application discussed in-depth understanding structure-property relationships provided. Finally, perspective future directions challenges this field presented further studies.

Язык: Английский

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Water-dispersible PEG-curcumin/amine-functionalized covalent organic framework nanocomposites as smart carriers for in vivo drug delivery

Nature Communications, Год журнала: 2018, Номер 9(1)

Опубликована: Июль 11, 2018

Covalent organic frameworks (COFs) as drug-delivery carriers have been mostly evaluated in vitro due to the lack of COFs nanocarriers that are suitable for vivo studies. Here we develop a series water-dispersible polymer-COF nanocomposites through assembly polyethylene-glycol-modified monofunctional curcumin derivatives (PEG-CCM) and amine-functionalized (APTES-COF-1) drug delivery. The real-time fluorescence response shows efficient tracking COF-based materials upon cellular uptake anticancer (doxorubicin (DOX)) release. Notably, studies demonstrate PEG-CCM@APTES-COF-1 is smart carrier delivery with superior stability, intrinsic biodegradability, high DOX loading capacity, strong stable fluorescence, prolonged circulation time improved accumulation tumors. More intriguingly, PEG350-CCM@APTES-COF-1 presents an effective targeting strategy brain research. We envisage represent great promise toward development multifunctional platform cancer-targeted

Язык: Английский

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3D Porphyrin-Based Covalent Organic Frameworks

Journal of the American Chemical Society, Год журнала: 2017, Номер 139(25), С. 8705 - 8709

Опубликована: Июнь 8, 2017

The design and synthesis of three-dimensional covalent organic frameworks (3D COFs) bearing photoelectric units have been considered as a big challenge. Herein, for the first time, we reported targeted two 3D porphyrin-based COFs (3D-Por-COF 3D-CuPor-COF), starting from tetrahedral (3D-Td) square (2D-C4) building blocks connected through [4 + 4] imine condensation reactions. On basis structural characterizations, 3D-Por-COF 3D-CuPor-COF are microporous materials with high surface areas, proposed to adopt 2-fold interpenetrated pts topology Pmc21 space group. Interestingly, both photosensitive can be used heterogeneous catalyst generating singlet oxygen under photoirradiation. However, shows enhanced photocatalytic activity compared 3D-CuPor-COF, indicating properties tuned by metalation porphyrin rings. results here will greatly inspire us synthesize other metalloporphyrins interesting applications (e.g., catalysis) in future.

Язык: Английский

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