A Stable Crown Ether Complex with a Noble‐Gas Compound

Crown ethers have been known for over 50 years, but no example of a complex between a noble-gas compound and a crown ether or another polydentate ligand had previously been reported. Xenon trioxide is shown to react with 15-crown-5 to form the kinetically stable (CH₂ CH₂ O)₅ XeO₃ adduct, which, in marked contrast with solid XeO₃ , does not detonate when mechanically shocked. The crystal structure shows that the five oxygen atoms of the crown …