New luminescent 1-aza-15-crown-5 ethers bearing a coumarin unit were synthesised leading to the cavitand-based calix crown ether 9. The solid-state structures of crown ethers 5 and 6 and the solid-state structures of the sodium and potassium iodide complexes of crown ether 5 are presented. The association constants for the complex formation with alkalimetalions in methanol were determined. Only weak