Britannica
Sources used in this answer
Which crown ether forms a complex with sodium ions?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
The crown ether that forms a complex with sodium ions (Na⁺) is 15-crown-5.
Crown ethers are cyclic molecules that exhibit size-selectivity for specific alkali cations based on the dimensions of the hole in the center of the ring. According to the research of chemist Charles J. Pedersen, the selectivity of these ethers is determined by their ring size:
- 12-crown-4 is selective for lithium ions (Li⁺).
- 15-crown-5 is selective for sodium ions (Na⁺).
- 18-crown-6 is selective for potassium ions (K⁺).1