Related Experiment Video
Updated: Jul 6, 2026
09:34
Synthesis of Information-bearing Peptoids and their Sequence-directed Dynamic Covalent Self-assembly
Published on: February 6, 2020
Anion-modulated reversible conversion of molecular assembly between a macrocycle and a linear chain
Huaze Dong1, Juan Yang, Xia Liu
1State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, China.
Inorganic Chemistry
|March 29, 2008
Summary
A flexible thioether ligand formed two distinct mercury compounds, a macrocycle and a 1D polymer. Anion presence dictated the structures, which could be reversibly altered.
Area of Science:
- Coordination chemistry
- Supramolecular chemistry
- Materials science
Background:
- Flexible thioether ligands offer versatile coordination possibilities.
- Mercury(II) compounds exhibit diverse structural behaviors.
- Anion templating is a key strategy in crystal engineering.
Purpose of the Study:
- To investigate the coordination behavior of a flexible thioether ligand with mercury(II).
- To explore the influence of different anions on the resulting supramolecular structures.
- To determine if the observed structural changes are reversible.
Main Methods:
- Synthesis of mercury(II) acetate and mercury(II) iodide complexes.
- Single-crystal X-ray diffraction analysis to elucidate structures.
- Variable temperature studies to assess structural reversibility.
Main Results:
- Two distinct compounds were formed: a macrocyclic complex and a 1D polymeric chain.
- The structural motifs (macrocycle vs. polymer) were found to be critically dependent on the nature of the anion (acetate vs. iodide).
- Reversible structural transformations between the macrocyclic and polymeric forms were observed upon anion exchange.
Conclusions:
- The flexible thioether ligand can adopt different coordination modes leading to diverse supramolecular architectures.
- Anions play a crucial role in directing the self-assembly of mercury(II)-thioether complexes.
- The observed structural plasticity offers potential for developing responsive materials.
Related Concept Videos
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.
01:20Anionic Chain-Growth Polymerization: Overview
The polymerization process that involves carbanion as an intermediate is called anionic polymerization. It is also a type of addition or chain-growth polymerization. Anionic polymerization gets initiated by a strong nucleophile such as an organolithium or a Grignard reagent. The most commonly used initiator for anionic polymerization is butyl lithium. Monomers involved in anionic polymerization must possess a vinyl group bonded to one or two electron-withdrawing groups. For instance,...
00:57Cationic Chain-Growth Polymerization: Mechanism
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...
01:17Radical Chain-Growth Polymerization: Chain Branching
The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical polymerization results in a low-density grade of polyethylene with a heavily branched skeletal structure. Here, the radical site abstracts hydrogen from the growing chain, and the radical site shifts from the end (a primary carbon center) to anywhere within the growing chain (a secondary carbon center). Consequently, the part of the chain from the...
01:28ATP and Macromolecule Synthesis
Biological macromolecules are organic compounds, predominantly composed of carbon atoms. The carbon atoms are covalently bonded with hydrogen, oxygen, nitrogen, and other minor elements. There are four major biological macromolecule classes: carbohydrates, lipids, proteins, and nucleic acids.
Most macromolecules are composed of single subunits, or building blocks, called monomers. The monomers combine with each other using covalent bonds to form larger molecules known as polymers.
Conversion of...
Most macromolecules are composed of single subunits, or building blocks, called monomers. The monomers combine with each other using covalent bonds to form larger molecules known as polymers.
Conversion of...
01:03Step-Growth Polymerization: Overview
Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...
Many natural and synthetic polymers are produced by...