Related Experiment Video
Updated: Oct 29, 2025
09:22
Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
8.0K
Optically active covalent organic frameworks and hyperbranched polymers with chirality induced by circularly
Yuting Wang1, Koji Yazawa2, Qingyu Wang1
1Institute for Catalysis (ICAT) and Graduate School of Chemical Sciences and Engineering, Hokkaido University, N21W10, Kita-ku, Sapporo 001-0021, Japan. tamaki.nakano@cat.hokudai.ac.jp.
Chemical Communications (Cambridge, England)
|July 13, 2021
Summary
Circularly polarized light induces axial chirality in covalent organic frameworks and hyperbranched polymers. Internal rotation dynamics, studied via NMR, explain variations in induction efficiency.
Area of Science:
- Materials Science
- Organic Chemistry
- Spectroscopy
Background:
- Covalent organic frameworks (COFs) and hyperbranched polymers are advanced materials with tunable properties.
- Inducing chirality in these materials is crucial for applications in asymmetric catalysis and chiroptical devices.
- Controlling the efficiency of chirality induction remains a significant challenge.
Purpose of the Study:
- To investigate the induction of axial chirality in COFs and hyperbranched polymers using circularly polarized light.
- To elucidate the relationship between internal rotation dynamics and the efficiency of chirality induction.
- To provide a mechanistic understanding of light-induced chiral transformations in these materials.
Main Methods:
- Synthesis of covalent organic frameworks and hyperbranched polymers with specific core and linker units.
- Irradiation with circularly polarized light to induce axial chirality.
- Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy, including Cross-Polarization Magic-Angle Spinning (CPMAS) and Chemical Exchange Saturation Transfer (CODEX) experiments, to study molecular dynamics.
Main Results:
- Successful induction of axial chirality in both covalent organic frameworks and hyperbranched polymers.
- Demonstration of varying induction efficiencies based on material structure.
- Correlation of internal rotation dynamics, revealed by NMR experiments, with the observed induction efficiencies.
Conclusions:
- Circularly polarized light is an effective tool for inducing axial chirality in designed organic materials.
- Internal rotation dynamics play a critical role in determining the efficiency of light-induced chiral induction.
- The findings offer insights into controlling supramolecular chirality in polymers and frameworks.
More Related Videos
08:42Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface
Published on: July 10, 2017
13.7K
06:16Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering
Published on: December 21, 2017
5.8K
Related Concept Videos
02:24Properties of Enantiomers and Optical Activity
19.3K
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
19.3K
02:05Prochirality
4.2K
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
4.2K
02:25Molecules with Multiple Chiral Centers
14.0K
Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...
14.0K
01:26Polymer Classification: Stereospecificity
2.9K
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
2.9K
02:25Chirality
27.5K
Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
27.5K
02:52Stereoisomerism
12.8K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
12.8K