become naked nucleophiles. For example, using 18-crown-6, potassium acetate is a more powerful nucleophile in organic solvents: [K(18-crown-6)+]OAc− + C6H5CH2Cl → C6H5CH2OAc + [K(18-crown-6)+]Cl− The first electride salt to be examined with X-ray crystallography, [Cs(18-crown-6)2]+·e−, was synthesized in 1983. This highly air- and moisture-sensitive solid has a sandwich molecular structure, where the electron is trapped within nearly spherical lattice cavities. However, the shortest electron-electron distance is too long (8.68 Å) to make this material a conductor of electricity. References External links Sigma Aldrich chemical profile Crown ethers Macrocycles