Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Deformation in a Circular Shaft01:10

Deformation in a Circular Shaft

933
One of the distinctive characteristics of circular shafts is their ability to maintain their cross-sectional integrity under torsion. In other words, each cross-section continues to exist as a flat, unaltered entity, simply rotating like a solid, rigid slab. To understand the distribution of shearing stress within such a shaft, consider a cylindrical section inside this circular shaft. This section has a length of L and a radius of R, with one end fixed. The radius of the cylindrical section is...
933
Stress Concentrations in Circular Shafts01:18

Stress Concentrations in Circular Shafts

586
Consider the elastic torsion formula, which applies to a circular shaft with a consistent cross-section. This formula assumes that the shaft's ends are loaded with rigid plates firmly attached. However, in many cases, torques are applied to the shaft through mechanisms like flange couplings or gears, which are connected by keys inserted into keyways. This application method modifies the stress distribution near the point of torque application, causing it to deviate from the distributions...
586
Uniform Circular Motion01:14

Uniform Circular Motion

22.4K
Uniform circular motion is a specific type of motion in which an object travels in a circle with a constant speed. For example, any point on a propeller spinning at a constant rate is undergoing uniform circular motion. The second, minute, and hour hands of a watch also undergo uniform circular motion. It is hard to believe that points on these rotating objects are actually accelerating, even though the rotation rate is constant. To understand this, we must analyze the motion in terms of...
22.4K
Non-uniform Circular Motion01:22

Non-uniform Circular Motion

9.7K
In uniform circular motion, the particle executing circular motion has a constant speed, and the circle is at a fixed radius. However, not all circular motion occurs at a constant speed. A particle can travel in a circle and speed up or slow down, showing an acceleration in the direction of motion. In that case, the motion is called non-uniform circular motion, and an additional acceleration is introduced, which is in the direction tangential to the circle. 
For example, such...
9.7K
Dynamics of Circular Motion01:30

Dynamics of Circular Motion

25.5K
An object undergoing circular motion, like a race car, is accelerating because it is changing the direction of its velocity. This centrally directed acceleration is called centripetal acceleration. This acceleration acts along the radius of the curved path (thus is also referred to as radial acceleration).
Any acceleration must be produced by some force. Therefore, any force or combination of forces can cause centripetal acceleration. A few examples include the tension in the rope on a...
25.5K
Molecular Models02:00

Molecular Models

43.9K
Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules.
43.9K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Inverted metal-free active template synthesis of rotaxanes via axle‑mediated macrocyclization.

Nature chemistry·2026
Same author

Trefoil polymers from a knotted synthon.

Nature chemistry·2026
Same author

One- and two-electron coordinatively-induced reduction of <i>N</i>-heterocycles by divalent rare earth terphenyl anilide complexes.

Chemical science·2026
Same author

Synthesis and Characterization of Monomeric, Dimeric, and Polymeric Rare-Earth Bis(trimethyl)silylphosphide Complexes.

Inorganic chemistry·2026
Same author

Conformationally Switchable Molecular Trefoil Knot Assembled From 2,6-Bis(1,2,3-triazol-4-yl)pyridine (btp) Building Blocks.

Journal of the American Chemical Society·2026
Same author

Coordination Chemistry of a Star of David [2]Catenand.

Journal of the American Chemical Society·2026

Related Experiment Video

Updated: Feb 13, 2026

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
09:22

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Published on: February 7, 2017

8.3K

Molecular Trefoil Knot from a Trimeric Circular Helicate.

Liang Zhang1, David P August1, Jiankang Zhong1

  • 1School of Chemistry , University of Manchester , Manchester M13 9PL , U.K.

Journal of the American Chemical Society
|March 15, 2018
PubMed
Summary

Researchers synthesized a molecular trefoil knot using a two-step process. This method achieved a 90% yield via self-assembly and ring-closing metathesis, creating complex molecular architectures.

More Related Videos

Helical Organization of Blood Coagulation Factor VIII on Lipid Nanotubes
12:24

Helical Organization of Blood Coagulation Factor VIII on Lipid Nanotubes

Published on: June 3, 2014

12.7K
Use of Alu Element Containing Minigenes to Analyze Circular RNAs
13:10

Use of Alu Element Containing Minigenes to Analyze Circular RNAs

Published on: March 10, 2020

7.8K

Related Experiment Videos

Last Updated: Feb 13, 2026

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
09:22

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Published on: February 7, 2017

8.3K
Helical Organization of Blood Coagulation Factor VIII on Lipid Nanotubes
12:24

Helical Organization of Blood Coagulation Factor VIII on Lipid Nanotubes

Published on: June 3, 2014

12.7K
Use of Alu Element Containing Minigenes to Analyze Circular RNAs
13:10

Use of Alu Element Containing Minigenes to Analyze Circular RNAs

Published on: March 10, 2020

7.8K

Area of Science:

  • Supramolecular Chemistry
  • Organic Synthesis
  • Chemical Crystallography

Background:

  • Molecular knots are complex topological structures with potential applications in materials science and nanotechnology.
  • Previous methods for synthesizing molecular knots often involve multi-step procedures with low yields.

Purpose of the Study:

  • To develop an efficient two-step synthesis for a molecular trefoil knot.
  • To investigate the self-assembly of a 12-component zinc helicate as a key intermediate.

Main Methods:

  • Self-assembly of a 12-component trimeric circular zinc helicate.
  • Ring-closing metathesis of pendant alkene chains on the helicate intermediate.
  • Characterization using NMR spectroscopy, mass spectrometry, and X-ray crystallography.

Main Results:

  • Successful two-step synthesis of a molecular trefoil knot.
  • Achieved an overall yield of 90% for the trefoil knot.
  • Confirmed the structures of both the intermediate helicate and the final trefoil knot through spectroscopic and crystallographic analyses.

Conclusions:

  • The reported method provides an efficient route to molecular trefoil knots.
  • The study demonstrates the utility of self-assembly and ring-closing metathesis in constructing complex molecular topologies.
  • The characterized trefoil knot serves as a foundation for exploring new functional materials.