Related Experiment Video
Updated: Jul 17, 2026
06:35
Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Hierarchical chiral framework based on a rigid adamantane tripod on Au(111)
Satoshi Katano1, Yousoo Kim, Hiroaki Matsubara
1Surface Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 Japan.
Journal of the American Chemical Society
|February 7, 2007
Summary
Bromo adamantane trithiol (BATT) molecules form ordered, chiral self-assembled monolayers on Au(111). Achiral monomers self-assemble into chiral trimers and hexagonal supermolecules, demonstrating a unique chiral phase transition.
Area of Science:
- Surface Science
- Supramolecular Chemistry
- Nanotechnology
Background:
- Self-assembled monolayers (SAMs) are crucial for surface functionalization.
- Understanding molecular self-assembly on surfaces is key to designing nanoscale structures.
- Chirality in molecular assemblies influences material properties.
Purpose of the Study:
- Investigate the adsorption and self-assembly of bromo adamantane trithiol (BATT) on Au(111).
- Determine the structural organization and chirality of BATT SAMs.
- Elucidate the factors driving chiral ordering and phase transitions.
Main Methods:
- Scanning tunneling microscopy (STM) at cryogenic temperatures (4.7 K).
- Analysis of molecular adsorption and self-assembly on Au(111) surfaces.
Main Results:
- BATT forms highly ordered SAMs on Au(111) with three-point contacts.
- A two-tiered hierarchical chiral organization is observed: chiral trimers from achiral monomers, forming chiral hexagonal supermolecules.
- Chiral phase transitions occur, transforming from racemic mixtures to enantiomeric domains.
- Stabilization by sulfur atoms and chirality induced by methylene groups are identified as key structural factors.
Conclusions:
- BATT molecules exhibit complex chiral self-assembly on Au(111).
- Hierarchical organization and chiral phase transitions are driven by molecule-substrate and intermolecular interactions.
- The study provides insights into controlling chirality in 2D molecular systems.
More Related Videos
08:25Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)
Published on: January 17, 2020
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Related Concept Videos
02:05Prochirality
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...
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
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...
02:25Chirality
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...
02:25Molecules with Multiple Chiral Centers
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...
01:19Structure of Amines
The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which is less than the tetrahedral angle of 109.5°. However, the C–N–H bond angle is slightly larger at 112°, with a carbon–nitrogen bond length of 147 pm. This carbon–nitrogen bond length of of amines is longer than the carbon–oxygen bond of alcohols (143 pm) but shorter than alkanes’ carbon–carbon bond (154 pm). These aspects are illustrated in Figure...
02:21Naming Enantiomers
The naming of enantiomers employs the Cahn–Ingold–Prelog rules that involve assigning priorities to different substituent groups at a chiral center. Each enantiomer, being a distinct molecule, is assigned a unique name by the Cahn–Ingold–Prelog (CIP) rules, also called the R–S system. The prefix R- or S- attached to the chiral centers in an enantiomer is dependent on the spatial arrangement of the four substituents on the chiral center. The R–S system essentially comprises three steps:...