Related Experiment Video
Updated: Jul 16, 2026
08:40
Light-driven Molecular Motors on Surfaces for Single Molecular Imaging
Published on: March 13, 2019
Molecular switch based on a cucurbit[6]uril containing bistable [3]rotaxane.
Dönüs Tuncel1, Ozgür Ozsar, H Burak Tiftik
1Department of Chemistry, Bilkent University, 06800, Ankara, Turkey. dtuncel@fen.bilkent.edu.tr
Chemical Communications (Cambridge, England)
|March 23, 2007
Summary
A novel bistable cyclodextrin-based [3]rotaxane was synthesized efficiently. This molecular switch demonstrates reversible conformational changes in response to stimuli like base, acid, and heat.
Area of Science:
- Supramolecular Chemistry
- Organic Synthesis
Background:
- Rotaxanes are mechanically interlocked molecules with potential applications in molecular machines.
- Controlling the movement of components within rotaxanes is key to developing responsive materials.
Purpose of the Study:
- To synthesize a bistable cyclodextrin-based [3]rotaxane.
- To investigate its behavior as a reversible molecular switch.
Main Methods:
- Efficient synthesis via CB6-catalyzed 1,3-dipolar cycloaddition.
- Characterization of the rotaxane structure and properties.
Main Results:
- High yield preparation of a bistable [3]rotaxane featuring two recognition sites.
- Demonstrated reversible switching behavior triggered by base, acid, and heat stimuli.
- Observed conformational changes due to controllable ring movement.
Conclusions:
- The synthesized rotaxane functions effectively as a molecular switch.
- Stimuli-responsive movement of rings enables controllable conformational changes.
Related Concept Videos
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
02:33Stereoisomerism of Cyclic Compounds
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
02:02Chair Conformation of Cyclohexane
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
![[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12422.jpg&w=3840&q=75)
01:21[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.
01:05Mechanism of Ciliary Motion
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...