scholarly journals Constructing covalent organic frameworks in waterviadynamic covalent bonding

IUCrJ ◽  
2016 ◽  
Vol 3 (6) ◽  
pp. 402-407 ◽  
Author(s):  
Jayshri Thote ◽  
Harshitha Barike Aiyappa ◽  
Raya Rahul Kumar ◽  
Sharath Kandambeth ◽  
Bishnu P. Biswal ◽  
...  
Keyword(s):  
Schiff Base ◽  
Covalent Bonding ◽  
Porous Polymers ◽  
Porous Structures ◽  
Covalent Organic Frameworks ◽  
Synthetic Route ◽  
Dynamic Covalent Chemistry ◽  
Water Based ◽  
First Time ◽  
Reaction In Water

The formation of keto-enamine based crystalline, porous polymers in water is investigated for the first time. Facile access to the Schiff base reaction in water has been exploited to synthesize stable porous structures using the principles of Dynamic Covalent Chemistry (DCC). Most credibly, the water-based Covalent Organic Frameworks (COFs) possess chemical as well as physical properties such as crystallinity, surface area and porosity, which is comparable to their solvothermal counterparts. The formation of COFs in water is further investigated by understanding the nature of the monomers formed using hydroxy and non-hydroxy analogues of the aldehyde. This synthetic route paves a new way to synthesize COFs using a viable, greener route by utilization of the DCC principles in conjunction with the keto–enol tautomerism to synthesize useful, stable and porous COFs in water.

Design and application of covalent organic frameworks for ionic conduction

2021 ◽  
Author(s):  
Xiuyu Zhao ◽  
Yao Chen ◽  
Zhifang Wang ◽  
Zhenjie Zhang
Keyword(s):  
Ionic Conduction ◽  
Porous Polymers ◽  
Porous Structures ◽  
Covalent Organic Frameworks ◽  
New Class ◽  
Ordered Porous ◽  
Design And Application

Covalent organic frameworks (COFs) are a new class of crystalline porous polymers that have received extensive attention from researchers in various backgrounds. Attributed to their highly ordered porous structures, outstanding...

scholarly journals The Macroscopic Covalent Organic Framework Architectures for Water Remediation

2021 ◽  
Author(s):  
Abdul Khayum Mohammed ◽  
Dinesh Shetty
Keyword(s):  
Organic Molecules ◽  
Three Dimensional ◽  
Water Remediation ◽  
Porous Polymers ◽  
Covalent Organic Frameworks ◽  
Dynamic Covalent Chemistry ◽  
Covalent Organic Framework ◽  
Synthetic Strategy ◽  
Organic Framework

Covalent organic frameworks (COFs) are two- (2D) or three-dimensional (3D) crystalline and porous polymers constructed from organic molecules with various symmetries. The reticular synthetic strategy and the dynamic covalent chemistry...

Formation and Trapping of the Thermodynamically Unfavoured Inverted-Hemicucurbit[6]uril

2019 ◽  
Author(s):  
Elena Prigorchenko ◽  
Sandra Kaabel ◽  
Triin Narva ◽  
Anastassia Baškir ◽  
Maria Fomitšenko ◽  
...  
Keyword(s):  
Complex Formation ◽  
Combinatorial Chemistry ◽  
Trifluoroacetic Acid ◽  
Chloride Anion ◽  
Binding Affinities ◽  
Dynamic Covalent Chemistry ◽  
Reaction Selectivity ◽  
Low Concentration ◽  
Dynamic Combinatorial Chemistry ◽  
First Time

Amplification of a thermodynamically unfavoured macrocyclic product through the directed shift of the equilibrium between dynamic covalent chemistry library members is difficult to achieve. We show for the first time that during condensation of formaldehyde and <i>cis</i>-<i>N,N'</i>-cyclohexa-1,2-diylurea formation of <i>inverted-cis</i>-cyclohexanohemicucurbit[6]uril (<i>i-cis</i>-cycHC[6]) can be induced at the expense of thermodynamically favoured <i>cis</i>-cyclohexanohemicucurbit[6]uril (<i>cis</i>-cycHC[6]). The formation of <i>i-cis-</i>cycHC[6] is enhanced in low concentration of the templating chloride anion and suppressed in excess of this template. We found that reaction selectivity is governed by the solution-based template-aided dynamic combinatorial chemistry and continuous removal of the formed cycHC[6] macrocycles from the equilibrating solution by precipitation. Notably, the <i>i-cis</i>-cycHC[6] was isolated with 33% yield. Different binding affinities of three diastereomeric <i>i-cis</i>-, <i>cis</i>-cycHC[6] and their chiral isomer (<i>R,R</i>)-cycHC[6] for trifluoroacetic acid demonstrate the influence of macrocycle geometry on complex formation.

Facile template synthesis of water-soluble triazine-based Schiff base ligand bridged-coordination polymers of Co(ii), Ni(ii), and Cu(ii): structure, biomolecular interactions, and cytotoxic activity

2019 ◽  
Vol 43 (34) ◽  
pp. 13371-13380 ◽  
Author(s):  
Sheikdawood Parveen ◽  
Thathan Premkumar ◽  
Hung Huy Nguyen ◽  
Subbiah Govindarajan
Keyword(s):  
Schiff Base ◽  
Cytotoxic Activity ◽  
Coordination Polymers ◽  
Schiff Base Ligand ◽  
Template Synthesis ◽  
Water Soluble ◽  
Biomolecular Interactions ◽  
First Time ◽  
Ct Dna

For the first time, a new hydrazone Schiff base ligand and its Co(ii), Ni(ii), and Cu(ii) complexes were synthesised and characterised. Their antioxidant and binding activities towards CT-DNA and BSA were evaluated.

Crystalline quantum dots of covalent organic frameworks for fast and sensitive detection of uranium

2020 ◽  
Vol 56 (6) ◽  
pp. 880-883 ◽  
Author(s):  
Meicheng Zhang ◽  
Yang Li ◽  
Lijian Ma ◽  
Xinghua Guo ◽  
Xiaofeng Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Sensitive Detection ◽  
Covalent Organic Frameworks ◽  
First Time

A crystalline quantum dot of a COF was prepared for the first time by original BRB method for fast uranium detection.

Electrochemical Synthesis of Hydroxyapatite Nanosheet-Assembled Porous Structures with Bipolar Membrane

2020 ◽  
Vol 841 ◽  
pp. 124-131
Author(s):  
Adrian Nur ◽  
Anatta Wahyu Budiman ◽  
Arif Jumari ◽  
Nazriati Nazriati ◽  
Fauziatul Fajaroh
Keyword(s):  
High Specific Surface Area ◽  
Electrolysis Cell ◽  
Loading Capacity ◽  
Anode Chamber ◽  
Porous Structures ◽  
Electrolysis Time ◽  
Cathode Chamber ◽  
Bipolar Membrane ◽  
Ph Increase ◽  
First Time

The porous nanostructured hydroxyapatite (HA) has the high specific surface area and loading capacity that is useful for enhancing bioactivity, sinterability, densification, and the capacity for loading the drug, protein, heavy metals, etc. For the first time, the bipolar membrane in electrochemical method was developed for the synthesis of hydroxyapatite nanosheet-assembled porous structures. The bipolar membrane was installed in the electrolysis cell to separate the cell into two chambers. The bipolar membrane prevented the OH- ions to move away from the cathode chamber and the H+ ions to go to the cathode chamber. In this condition, HA was formed in the cathode chamber while the other calcium phosphate was formed in the anode chamber. The pH increase of solution rapidly leads to more effective the formation of the nanostructured HA. The higher the electrolysis time and the current density the greater the tendency of nanostructured HA formation. The mechanism of HA hydroxyapatite nanosheet-assembled porous structures formation includes the agglomeration formation of the spherical-like particles, the formation of agglomeration nanosheet structures, and the formation of HA hydroxyapatite nanosheet-assembled porous structures.

scholarly journals Force spectroscopy-based simultaneous topographical and mechanical characterization to study polymer-to-polymer interactions in coated alginate microspheres

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria Virumbrales-Muñoz ◽  
Edorta Santos-Vizcaino ◽  
Laura Paz ◽  
Amparo Maria Gallardo-Moreno ◽  
Gorka Orive ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Mechanical Characterization ◽  
Force Spectroscopy ◽  
Covalent Bonding ◽  
Design Rationale ◽  
Polymer Interactions ◽  
First Time ◽  
Hydrogel Microspheres

AbstractCell-laden hydrogel microspheres have shown encouraging outcomes in the fields of drug delivery, tissue engineering or regenerative medicine. Beyond the classical single coating with polycations, many other different coating designs have been reported with the aim of improving mechanical properties and in vivo performance of the microspheres. Among the most common strategies are the inclusion of additional polycation coatings and the covalent bonding of the semi-permeable membranes with biocompatible crosslinkers such as genipin. However, it remains challenging to characterize the effects of the interactions between the polycations and the hydrogel microspheres over time in vitro. Here we use a force spectroscopy-based simultaneous topographical and mechanical characterization to study polymer-to-polymer interactions in alginate microspheres with different coating designs, maintaining the hydrogels in liquid. In addition to classical topography parameters, we explored, for the first time, the evolution of peak/valley features along the z axis via thresholding analysis and the cross-correlation between topography and stiffness profiles with resolution down to tens of nanometers. Thus, we demonstrated the importance of genipin crosslinking to avoid membrane detachment in alginate microspheres with double polycation coatings. Overall, this methodology could improve hydrogel design rationale and expedite in vitro characterization, therefore facilitating clinical translation of hydrogel-based technologies.

scholarly journals Multifunctional carbon nanotubes covalently coated with imine-based covalent organic frameworks: exploring structure–property relationships through nanomechanics

Nanoscale ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 1128-1137 ◽  
Author(s):  
Alicia Moya ◽  
Mercedes Hernando-Pérez ◽  
Marta Pérez-Illana ◽  
Carmen San Martín ◽  
Julio Gómez-Herrero ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Synthesis ◽  
Covalent Organic Frameworks ◽  
Structure Property ◽  
One Pot ◽  
Covalent Organic Framework ◽  
Mwcnt Surface ◽  
Structure Property Relationships ◽  
First Time ◽  
Organic Framework

Hybridization of imine-based covalent organic framework (COF-300) on oxidized MWCNT surface have been designed and succesfully developed for the first time in one-pot chemical synthesis.

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