Crown Compounds

Aza Crown Compounds; Aza-Thia Crown Compounds; Thia Crown Compounds; Aza Thia Crown Compounds; Compounds, Aza Crown; Compounds, Aza-Thia Crown; Compounds, Crown; Compounds, Thia Crown; Crown Compounds, Aza; Crown Compounds, Aza-Thia
Macrocyclic compounds analogous to CROWN ETHERS but which lack any OXYGEN atoms.