quently the temperature was slowly decreased and the mixture heated at 500ЊC for 7 days. A brown, fine crystal-
The synthesis of rubidium heptachlorodiuranate(III) together with some of its structural, spectroscopic, and magnetic line powder was obtained. The compound is not resistant properties are reported. Unit cell parameters were determined to oxidation by air and should be stored under nitrogen from X-ray powder diffraction data. Uranium(3؉) doped single in sealed tubes. It is easily soluble in water and a number crystals of RbY 2 Cl 7 have been grown by the Bridgmanof more polar organic solvents such as methanol, ethanol, Stockbarger method. The Raman and infrared spectra of formic acid, and formamide.
RbU 2 Cl 7 as well as the electronic absorption spectrum of
Single crystals of RbY 2 Cl 7 : U 3ϩ with a uranium concen-RbY 2 Cl 7 : U 3؉ (1%) at 4.2 K have been recorded and are dis-tration of 0.1 and 1% were grown by the Bridgmancussed. Magnetic susceptibility measurements were carried out Stockbarger method using RbU 2 Cl 7 as the doping subby the Faraday method in the 4.2-300 K range. The Curiestance. Polished plates of RbY 2 Cl 7 : U 3ϩ of 0.52-mm (1%) Weiss law is followed in the 210-300 K range with the paramagand 1.0-mm (0.1%) thick were used for electronic absorpnetic constants eff ؍ 3.74 B , C ؍ 1.750 emu ؒ K ؒ mole ؊1 , and tion measurements in the 4000-13,000 cm Ϫ1 and 12,000-؍ ؊80 K.