Description

21-Crown-7 is a high-purity macrocyclic polyether, specifically a crown ether, with the CAS registry number 33089-36-0. This compound is a critical tool in supramolecular chemistry, valued for its exceptional ability to selectively bind alkali metal cations, particularly potassium ions, due to its precise cavity size. It is essential for researchers and process chemists in advanced material science, catalysis, and analytical chemistry who require specific ion transport, phase-transfer catalysis, or molecular recognition capabilities.

Application

• Phase-Transfer Catalysis (PTC): Facilitates reactions between reagents in immiscible phases, enhancing reaction rates and yields in organic synthesis.
• Ion-Selective Electrodes & Sensors: Serves as a key ionophore in membrane formulations for detecting and measuring potassium ion concentrations.
• Molecular Recognition & Host-Guest Chemistry: Used as a building block for constructing more complex supramolecular assemblies and molecular machines.
• Metal Ion Separation & Extraction: Enables the selective separation and purification of specific alkali metal ions from complex mixtures.
• Polymer & Material Modification: Incorporated into polymers to create ion-conductive materials or to impart specific binding properties.
• Analytical Chemistry: Acts as a masking agent or complexing agent to improve selectivity in chromatographic separations and spectroscopic analyses.

Basic Information

Product Name	21-Crown-7
CAS No.	33089-36-0
Molecular Formula	C14H28O7
Molecular Weight	308.37 g/mol
Synonyms	1,4,7,10,13,16,19-Heptaoxacyclohenicosane; 21-Crown-7 Ether; 21C7; Heptaethylene glycol cyclic heptaether; 1,4,7,10,13,16,19-Heptaoxacycloheneicosane; DB21C7; [21]crown-7
EINECS	Contact for details

Quality Control

Our 21-Crown-7 is manufactured under strict quality management protocols. Each batch undergoes rigorous analytical testing, including NMR, HPLC, and Karl Fischer titration, to ensure high chemical purity and confirm identity. A comprehensive Certificate of Analysis (COA) detailing all test results is provided with every shipment to guarantee traceability and compliance with your research and development specifications.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). This product is hygroscopic (moisture-sensitive). Keep the container tightly sealed under an inert atmosphere (e.g., nitrogen or argon) to prevent moisture absorption and degradation.

Specification

Item	Specification
Appearance	Colorless to pale yellow liquid
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 97.0%
Water Content (KF)	≤ 0.5%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.