CS+(15-CROWN-5)2.E- - A CRYSTALLINE ANTIFERROMAGNETIC ELECTRIDE

The crystalline electride formed from cesium metal and 15-crown-5 contains sandwiched Cs+ cations and trapped electrons, the latter presumably centered at relatively isolated anionic sits. The magnetic susceptibility obeys the Curie-Weiss law above about 15 K, and annealed polycrystalline samples show an antiferromagnetic transition at 4.6 K. At 1.6 K, spin alignment occurs in a magnetic field and is essentially complete above 0.3 T, indicating that the magnetic anisotropy is weak. The Cs-133 NMR spectrum and magnetic susceptibility as a function of temperature allowed the determination of the electron density at the cesium nucleus as only 0.063% that of a free cesium atom but nearly twice that found for Cs+(18-crown-6)2.e-. The properties and structure suggest electron localization in cavities similar to the anionic sites in Cs+(15-crown-5)2.Na-, with relatively weak interactions among the trapped electrons.