Smart covalent organic frameworks: dual channel sensors for acid and base

2021 ◽  
Author(s):  
Jia Xin Koh ◽  
Keyu Geng ◽  
Donglin Jiang
Keyword(s):  
Pore Wall ◽  
Covalent Organic Frameworks ◽  
Luminescent Sensors ◽  
Dual Channel ◽  
Acid And Base

The fully π-conjugated sp2 carbon covalent organic frameworks upon integration with carboxylic electrolyte sites on the pore wall develop highly luminescent sensors. The sensors feature dual channel responsiveness and enable...

scholarly journals Amine-linked Covalent Organic Frameworks as a Powerful Platform for Post-Synthetic Modification: Structure Interconversion and Combined Linkage- and Pore-Wall-Modification

2020 ◽  
Author(s):  
Lars Grunenberg ◽  
Gökcen Savasci ◽  
Maxwell Terban ◽  
Viola Duppel ◽  
Igor Moudrakovski ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Hydrolytic Stability ◽  
Pore Wall ◽  
Single Step ◽  
Synthetic Methods ◽  
Secondary Amines ◽  
Covalent Organic Frameworks ◽  
One Pot ◽  
Surface Areas ◽  
Novel Strategy

<div>Covalent organic frameworks 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 covalent organic frameworks, which serve as a scaffold enabling pore-wall modification and linkage-interconversion by new synthetic methods based on Leuckart-Wallach reduction with formic acid and ammonium formate. Frameworks connected entirely by secondary amine linkages, mixed amine/imine bonds, and partially formylated amine linkages are obtained in a single step from imine-linked frameworks, or directly from corresponding linkers in a one-pot crystallisation-reduction approach. The new, 2D amine-linked covalent organic frameworks, rPI-3-COF, rTTI-COF, and rPy1P-COF, are obtained with high crystallinity and large surface areas. Secondary amines, installed as reactive-sites on the pore wall, enable further post-synthetic functionalisation to access tailored covalent organic frameworks, with increased hydrolytic stability, as potential heterogeneous catalysts.</div>

Sequential pore wall functionalization in covalent organic frameworks and application to stable camptothecin delivery systems

2020 ◽  
Vol 117 ◽  
pp. 111263
Author(s):  
Artur De Santana Oliveira ◽  
Eva María Rivero-Buceta ◽  
Carla Vidaurre-Agut ◽  
Alechania Misturini ◽  
Victoria Moreno ◽  
...  
Keyword(s):  
Pore Wall ◽  
Delivery Systems ◽  
Covalent Organic Frameworks

scholarly journals Amine-linked Covalent Organic Frameworks as a Powerful Platform for Post-Synthetic Modification: Structure Interconversion and Combined Linkage- and Pore-Wall-Modification

2020 ◽  
Author(s):  
Lars Grunenberg ◽  
Gökcen Savasci ◽  
Maxwell Terban ◽  
Viola Duppel ◽  
Igor Moudrakovski ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Hydrolytic Stability ◽  
Pore Wall ◽  
Single Step ◽  
Synthetic Methods ◽  
Secondary Amines ◽  
Covalent Organic Frameworks ◽  
One Pot ◽  
Surface Areas ◽  
Novel Strategy

<div>Covalent organic frameworks 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 covalent organic frameworks, which serve as a scaffold enabling pore-wall modification and linkage-interconversion by new synthetic methods based on Leuckart-Wallach reduction with formic acid and ammonium formate. Frameworks connected entirely by secondary amine linkages, mixed amine/imine bonds, and partially formylated amine linkages are obtained in a single step from imine-linked frameworks, or directly from corresponding linkers in a one-pot crystallisation-reduction approach. The new, 2D amine-linked covalent organic frameworks, rPI-3-COF, rTTI-COF, and rPy1P-COF, are obtained with high crystallinity and large surface areas. Secondary amines, installed as reactive-sites on the pore wall, enable further post-synthetic functionalisation to access tailored covalent organic frameworks, with increased hydrolytic stability, as potential heterogeneous catalysts.</div>

scholarly journals Amine-Linked Covalent Organic Frameworks as a Platform for Postsynthetic Structure Interconversion and Pore-Wall Modification

2021 ◽  
Vol 143 (9) ◽  
pp. 3430-3438 ◽  
Author(s):  
Lars Grunenberg ◽  
Gökcen Savasci ◽  
Maxwell W. Terban ◽  
Viola Duppel ◽  
Igor Moudrakovski ◽  
...  
Keyword(s):  
Pore Wall ◽  
Covalent Organic Frameworks

Covalent organic frameworks: efficient, metal-free, heterogeneous organocatalysts for chemical fixation of CO2 under mild conditions

2018 ◽  
Vol 6 (2) ◽  
pp. 374-382 ◽  
Author(s):  
Yongfeng Zhi ◽  
Pengpeng Shao ◽  
Xiao Feng ◽  
Hong Xia ◽  
Yumin Zhang ◽  
...  
Keyword(s):  
Pore Wall ◽  
Chemical Fixation ◽  
Covalent Organic Frameworks ◽  
Metal Free ◽  
Heterogeneous Catalytic ◽  
Mild Conditions ◽  
Hydroxy Groups ◽  
Catalytic Performances

Covalent organic frameworks with hydroxy groups in the pore wall, which exhibit efficient, metal-free, heterogeneous catalytic performances for chemical fixation of CO2 under mild conditions, are reported.

scholarly journals Pore wall fluorescence labeling of covalent organic frameworks

CrystEngComm ◽  
2017 ◽  
Vol 19 (33) ◽  
pp. 4886-4891 ◽  
Author(s):  
Sabrina Rager ◽  
Mirjam Dogru ◽  
Veronika Werner ◽  
Andreij Gavryushin ◽  
Maria Götz ◽  
...  
Keyword(s):  
Pore Wall ◽  
Fluorescent Dye ◽  
Fluorescence Labeling ◽  
Covalent Organic Frameworks ◽  
Covalent Organic Framework ◽  
Organic Framework

A novel covalent organic framework (COF) based on terphenyldiboronic acid exhibiting open pores of about 4.1 nm is presented. The pore walls of the COF could be functionalized with a fluorescent dye.

scholarly journals Covalent Organic Frameworks: Synthesis, Properties and Applications—An Overview

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 970
Author(s):  
Tiago F. Machado ◽  
M. Elisa Silva Serra ◽  
Dina Murtinho ◽  
Artur J. M. Valente ◽  
Mu. Naushad
Keyword(s):  
Gas Adsorption ◽  
Pore Wall ◽  
Building Blocks ◽  
Pollutant Removal ◽  
Three Dimensions ◽  
Covalent Organic Frameworks ◽  
Vast Number ◽  
Microporous Polymers ◽  
Material Chemistry ◽  
Synthesis Properties

Covalent Organic Frameworks (COFs) are an exciting new class of microporous polymers with unprecedented properties in organic material chemistry. They are generally built from rigid, geometrically defined organic building blocks resulting in robust, covalently bonded crystalline networks that extend in two or three dimensions. By strategically combining monomers with specific structures and properties, synthesized COF materials can be fine-tuned and controlled at the atomic level, with unparalleled precision on intrapore chemical environment; moreover, the unusually high pore accessibility allows for easy post-synthetic pore wall modification after the COF is synthesized. Overall, COFs combine high, permanent porosity and surface area with high thermal and chemical stability, crystallinity and customizability, making them ideal candidates for a myriad of promising new solutions in a vast number of scientific fields, with widely varying applications such as gas adsorption and storage, pollutant removal, degradation and separation, advanced filtration, heterogeneous catalysis, chemical sensing, biomedical applications, energy storage and production and a vast array of optoelectronic solutions. This review attempts to give a brief insight on COF history, the overall strategies and techniques for rational COF synthesis and post-synthetic functionalization, as well as a glance at the exponentially growing field of COF research, summarizing their main properties and introducing the numerous technological and industrial state of the art applications, with noteworthy examples found in the literature.

TEM visualization of surface replicated acid and base catalyzed sol-gel glasses

1986 ◽  
Vol 44 ◽  
pp. 448-449
Author(s):  
George C. Ruben ◽  
Merrill W. Shafer
Keyword(s):  
Elevated Temperatures ◽  
Sol Gel ◽  
Basic Medium ◽  
Glass Transition Point ◽  
Structural Space ◽  
Acid And Base ◽  
Organometallic Precursors ◽  
New Processing ◽  
Gel Glasses ◽  
Physical Phenomena

Traditionally ceramics have been shaped from powders and densified at temperatures close to their liquid point. New processing methods using various types of sols, gels, and organometallic precursors at low temperature which enable densificatlon at elevated temperatures well below their liquidus, hold the promise of producing ceramics and glasses of controlled and reproducible properties that are highly reliable for electronic, structural, space or medical applications. Ultrastructure processing of silicon alkoxides in acid medium and mixtures of Ludox HS-40 (120Å spheres from DuPont) and Kasil (38% K2O &62% SiO2) in basic medium have been aimed at producing materials with a range of well defined pore sizes (∼20-400Å) to study physical phenomena and materials behavior in well characterized confined geometries. We have studied Pt/C surface replicas of some of these porous sol-gels prepared at temperatures below their glass transition point.

Covalent organic frameworks: an ideal platform for designing ordered materials and advanced applications

2021 ◽  
Author(s):  
Ruoyang Liu ◽  
Ke Tian Tan ◽  
Yifan Gong ◽  
Yongzhi Chen ◽  
Zhuoer Li ◽  
...  
Keyword(s):  
Covalent Organic Frameworks ◽  
2D And 3D ◽  
Advanced Applications

Covalent organic frameworks offer a molecular platform for integrating organic units into periodically ordered yet extended 2D and 3D polymers to create topologically well-defined polygonal lattices and built-in discrete micropores and/or mesopores.

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