Shared molecule
Chemistry · L5 · 18-Crown-6
A macrocyclic polyether with six ether oxygens lining an 18-membered ring. Its cavity diameter (~2.6–3.2 Å) closely matches the ionic diameter of K⁺, making it the textbook example of cavity-size selectivity in host–guest chemistry. SMILES: C1COCCOCCOCCOCCOCCO1.