Related Experiment Video
Updated: Aug 3, 2025
08:18
Microscopic Visualization of Porous Nanographenes Synthesized through a Combination of Solution and On-Surface Chemistry
Published on: March 4, 2021
1.8K
Induction of Chirality on Nanographenes
Saki Arimura1, Ikuya Matsumoto1, Shohei Nishitani1
1Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8526, Japan.
Chemistry, an Asian Journal
|April 10, 2023
Summary
Researchers enhanced the chirality of nanographenes (NGs) by adding bulky pyrene and m-terphenyl groups. These modifications improved circular dichroism signals and induced opposite chirality in the nanographenes.
Area of Science:
- Organic Chemistry
- Materials Science
- Nanotechnology
Background:
- Chirality induction in nanographenes (NGs) is crucial for their applications.
- Previous methods for chirality induction in NGs have limitations.
Purpose of the Study:
- To enhance the chirality of nanographenes through postsynthetic chemical modifications.
- To investigate the effect of bulky substituents on the circular dichroism (CD) signals of NGs.
Main Methods:
- Postsynthetic modification of NGs using pyrene and m-terphenyl groups via Pd-catalyzed cross-coupling reactions.
- Analysis of chirality using circular dichroism (CD) spectroscopy.
- Computational modeling using density functional theory (DFT) to understand structural influences.
Main Results:
- Bulky pyrene and m-terphenyl substituents significantly improved the induced CD signal of NGs.
- The modifications resulted in the induction of opposite chirality compared to previous studies.
- DFT calculations revealed that π/π and CH/π interactions between substituents influenced imide orientation and distorted NG edges, creating chiral environments.
Conclusions:
- Postsynthetic modification with bulky substituents is an effective strategy for enhancing chirality in nanographenes.
- The observed chirality induction and signal enhancement are attributed to substituent interactions and resulting edge distortions.
- These findings open possibilities for detecting CD signals in the visible region and controlling chirality in NGs.
Related Concept Videos
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
5.8K
Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
5.8K
02:05Prochirality
3.9K
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...
3.9K
02:30Chirality in Nature
13.6K
Chirality is the most intriguing yet essential facet of nature, governing life’s biochemical processes and precision. It can be observed from a snail shell pattern in a macroscopic world to an amino acid, the minutest building block of life. Most of the snails around the world have right-coiled shells because of the intrinsic chirality in their genes. All the amino acids present in the human body exist in an enantiomerically pure state, except for glycine - the sole achiral amino acid.
13.6K
02:25Chirality
24.6K
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...
24.6K
01:07Radicals: Electronic Structure and Geometry
4.1K
This lesson delves into the geometry of a radical, which is influenced by the electronic structure of the molecule. The principle is similar to that of a lone pair, where the unpaired electron influences the geometry at the radical center.
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
4.1K
02:18Fischer Projections
13.5K
Learning to draw Fischer projections of molecules and understanding their relevance plays a crucial role in the visual depiction of organic molecules. A Fischer projection is a two-dimensional projection on a planar surface to simplify the three-dimensional wedge–dash representation of molecules. This is especially helpful in the case of molecules with multiple chiral centers that can be difficult to draw. Here, all the bonds of interest are represented as horizontal or vertical lines.
13.5K