The combination of anhydrous SnCl4 with 18-crown-6 in aqueous conditions results in formation of the non-hydrolysed product [cis-SnCl 4(H2O)2]·18-crown-6·2H 2O. The X-ray crystal structure shows extensive intermolecular hydrogen bonding involving the cis-octahedral SnCl4(H 2O)2 units, the uncoordinated water molecules and the crown ether. Similarly, [2,2,2]cryptand reacts with an aqueous solution formed by adding anhydrous GaCl3 to slightly acidic water, affording [[2,2,2]cryptand+2H+][GaCl4]2.
- Crown ethers
- Hydrolytic stability