18-Crown-6丨CAS 17455-13-9

Overview

18-Crown-6丨CAS 17455-13-9 is one of the most well-known crown ethers, named for its ability to "crown" specific metal cations. It exhibits remarkable selectivity and binding affinity, especially for potassium ions (K⁺), making it a key compound in host–guest chemistry, coordination chemistry, and ion transport research.

Applications

1. Phase-Transfer Catalysis

18-Crown-6丨CAS 17455-13-9 facilitates ion transport between aqueous and organic phases, allowing reactions involving ionic reagents to proceed in organic solvents.

It is widely used in nucleophilic substitution reactions (SN2) where alkali metal salts are involved (e.g., KCN, KF).

2. Selective Metal Ion Complexation

Exhibits high selectivity for potassium (K⁺) ions due to size compatibility with its cavity.

Used in analytical chemistry to complex metal ions for separation, detection, or transport.

Enhances solubility of inorganic salts in nonpolar solvents.

3. Organic Synthesis

Acts as a reaction promoter or solubilizer by binding to metal cations and freeing nucleophilic anions.

Helps enable reactions under milder conditions and improves yields in otherwise slow or inefficient transformations.

4. Ion Transport and Membrane Research

Model compound in ion transport studies, mimicking biological ion channels.

Used to design ion-selective electrodes and study membrane permeability in supramolecular chemistry.

5. Host–Guest and Supramolecular Chemistry

Serves as a host molecule for alkali metal ions in complexation studies.

Forms stable inclusion complexes, useful for studying molecular recognition, binding affinity, and self-assembly.

Benefits

1. High Ion Selectivity

The cavity size (~2.6–3.2 Å) is ideal for K⁺, offering exceptional binding specificity.

2. Versatile Reaction Facilitator

Allows inorganic salts to react in organic media, bridging the gap between polar and nonpolar environments.

3. Enhanced Solubility and Reactivity

Increases solubility of metal salts, and boosts reactivity of nucleophiles by detaching the cation.

4. Widely Applicable Across Disciplines

Used in synthetic organic chemistry, analytical techniques, electrochemistry, and materials science.

Conclusion

18-Crown-6丨CAS 17455-13-9 is a powerful and selective macrocyclic ether used in phase-transfer catalysis, ion complexation, supramolecular chemistry, and membrane research. Its strong affinity for potassium ions and ability to enhance reactivity in both aqueous and organic media make it a versatile and indispensable tool in both academic and industrial chemical applications.