Related Experiment Video
Updated: May 16, 2026
09:22
Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Formation of a pillar[5]arene-based [3]pseudorotaxane in solution and in the solid state
Lingyan Gao1, Chengyou Han, Bo Zheng
1MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Chemistry, Zhejiang University, Hangzhou 310027, P. R. China.
Chemical Communications (Cambridge, England)
|December 4, 2012
Summary
Researchers successfully isolated a novel [3]pseudorotaxane using column chromatography. This supramolecular structure was found to comprise a copillar[5]arene and its monomer in a 2:1 ratio.
Area of Science:
- Supramolecular Chemistry
- Organic Synthesis
- Crystallography
Background:
- Pillar[5]arenes are macrocyclic compounds with potential applications in molecular recognition and self-assembly.
- The synthesis of complex supramolecular architectures like pseudorotaxanes often presents challenges in isolation and characterization.
- Understanding the stoichiometry and structure of host-guest complexes is crucial for designing functional molecular systems.
Purpose of the Study:
- To report the successful synthesis and isolation of a novel [3]pseudorotaxane.
- To elucidate the structural characteristics and stoichiometry of the synthesized pseudorotaxane.
- To demonstrate the utility of column chromatography in separating complex supramolecular assemblies.
Main Methods:
- Synthesis of copillar[5]arene.
- Separation of the [3]pseudorotaxane using column chromatography.
- Structural characterization via single crystal X-ray analysis.
Main Results:
- A novel [3]pseudorotaxane was successfully synthesized and isolated.
- Column chromatography proved effective for separating the pseudorotaxane from the reaction mixture.
- Single crystal X-ray analysis confirmed the pseudorotaxane's structure, revealing a 2:1 molar ratio of copillar[5]arene to its monomer.
Conclusions:
- The study demonstrates a viable method for the isolation of complex pseudorotaxanes.
- The determined 2:1 stoichiometry provides valuable structural insight into this specific host-guest complex.
- This work contributes to the synthetic toolkit for supramolecular chemistry, particularly in the field of pillararene derivatives.
Related Concept Videos
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...
01:18Aromatic Hydrocarbon Cations: Structural Overview
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
Removing one hydrogen from the intervening CH2 group with both...
02:11Conformations of Cyclohexane
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
01:04Anionic Chain-Growth Polymerization: Mechanism
The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael acceptor.
02:06Newman Projections
Different notations are used to represent the three-dimensional structure of molecules on two-dimensional surfaces. One of the most commonly used representations is the dash-wedge formula. The dashed wedges, solid wedges, and the plane lines indicate the groups situated behind the plane, coming out of the plane, and in the plane, respectively.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
01:18Aromatic Hydrocarbon Anions: Structural Overview
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous overlap of p...
Due to the absence of continuous overlap of p...