Oxygen Anion Solubility as a Factor in Molten Flux Crystal Growth, Synthesis, and Characterization of Four New Reduced Lanthanide Molybdenum Oxides: Ce_4.918(3)Mo₃O₁₆, Pr_4.880(3)Mo₃O₁₆, Nd_4.910(3)Mo₃O₁₆, and Sm_4.952(3)Mo₃O₁₆

Abstract

Four new reduced lanthanide molybdenum oxides containing mixed valent Mo(V/VI)O4 tetrahedra were prepared in single crystal form by utilizing a high temperature molten salt flux synthesis involving an in situ reduction step. Calculations support the experimentally observed result that large alkali metal cations such as cesium are superior compared to the smaller alkali metal cations such as sodium in solvating O2– to facilitate oxide crystal growth in halide melts. All four compounds were structurally characterized by single crystal and powder X-ray diffraction methods and were found to crystallize in the cubic space group Pn3̅n. The temperature dependence of the magnetic susceptibility of these compounds was measured, and all were found to exhibit simple paramagnetism.