Acta chemica Scandinavica/Acta chemica Scandinavica. B, Organic chemistry and biochemistry/Acta chemica Scandinavica. A, Physical and inorganic chemistry/Acta chemica Scandinavica. Series B. Organic chemistry and biochemistry/Acta chemica Scandinavica. Series A, Physical and inorganic chemistry · 1961 · 14 citations · 0 references
Natural SciencesChemistryMaterials ScienceCrystal StructureInorganic ChemistrySolid-state ChemistryCrystal ChemistryCrystallographyInorganic MaterialsMetal OxidesStructure DeterminationX-ray CrystallographyCrystallographic CharacterizationCrystallographic Data ReductionCrystallographic PolymorphismSingle-crystal X-ray DiffractionSpace Group RelationsSpace Group SymmetrySpace-group DeterminationStrontium Salts
Crystals of Sr/sub 2/CrO/sub 4/, suitable for single crystal x-ray studies, were prepared from chromium(III) oxide, strontium chromate(VI), and carbonate-free strontium hydroxide in a platinum crucible at 900 deg C with argon as a protecting gas. Approximate values of cell dimensions were obtained from Weissenberg photographs and more accurate values were then obtained from a Guinier powder photograph with strictly monochromatized CuK/sub 1/ radiation. The crystal was shown to be orthorhombic. All attempts to solve the structure on the basis of the space group No. 62 Pnma failed, and it was concluded that the space group might be No. 33 Pn2/sub 1/a. The distribution of the metal atoms indicates that Sr/sub 2/CrO/sub 4/ is isomorphous neither with K/sub 2/NiF/sub 4/ nor with K/sub 2/CrO/sub 4/, but that the structure very hikehy contains discrete four-coordinated chromium--oxygen complexes similar to those found in K/sub 2/CrO/ sub 4/. (P.C.H.)