Related Experiment Video
Updated: Aug 9, 2025
10:33
An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation
Published on: February 27, 2019
8.5K
Chiral Single-Molecule Potentiometers Based on Stapled ortho- Oligo(phenylene)ethynylenes
Ana M Ortuño1, Pablo Reiné1, Luis Álvarez de Cienfuegos1
1Departamento de Química Orgánica, Universidad de Granada (UGR), Unidad de Excelencia de Química Aplicada a la Biomedicina y Medioambiente (UEQ), Facultad de Ciencias, C. U. Fuentenueva, Spain.
Angewandte Chemie (International Ed. in English)
|February 22, 2023
Summary
We designed chiral molecular junctions with stress-dependent conductance. Their helical structure and spin filtering capabilities were confirmed using advanced computational methods.
Area of Science:
- Molecular Electronics
- Supramolecular Chemistry
- Computational Chemistry
Background:
- Chiral molecular junctions are crucial for spintronics.
- Controlling molecular helicity under mechanical stress is challenging.
Purpose of the Study:
- To chemically design chiral molecular junctions with stress-dependent conductance.
- To investigate the stability of helicity in single-molecule junctions.
- To explore their potential as unimolecular spin filters.
Main Methods:
- Chemical synthesis of novel chiral molecules.
- Single-molecule junction fabrication and conductance measurements.
- Density Functional Theory (DFT) calculations.
- Ab-initio estimation of CISS-originating spin polarization.
Main Results:
- Demonstrated stress-dependent conductance in chiral molecular junctions.
- Observed distinct conductive pathways linked to helical conformations.
- Confirmed helicity maintenance during molecular stretching.
- Theoretically proved large chiro-optical responses.
- Showcased potential as unimolecular spin filters with ab-initio spin polarization calculations.
Conclusions:
- The designed chiral molecules maintain helicity under stress, enabling tunable conductance.
- These molecules show promise for applications in molecular electronics and spintronics.
- First ab-initio calculation of CISS spin polarization for a realistic molecular system.
Related Concept Videos
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
00:58¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons
1.9K
Replacing each alpha-hydrogen in chloroethane by bromine (or a different functional group) yields a pair of enantiomers. Such protons are called prochiral or enantiotopic and are related by a mirror plane. Enantiotopic protons are chemically equivalent in an achiral environment. Because most proton NMR spectra are recorded using achiral solvents, enantiotopic hydrogens yield a single signal.
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
1.9K
01:26Polymer Classification: Stereospecificity
2.5K
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...
2.5K
02:25Molecules with Multiple Chiral Centers
11.9K
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...
11.9K
01:11ortho–para-Directing Activators: –CH3, –OH, –NH2, –OCH3
6.2K
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
6.2K
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