John M. Haschke

The preparation and some properties of europium bromides and hydrated bromides

Abstract Europium dibromide was prepared by dehydration and decomposition of an europium tribomide hexahydrate-ammonium bromide matrix and single crystals were grown by vapor transport techniques. Anhydrous europium tribromide was prepared by reaction of the dibromide with bromine at bromine pressures of between 12 and 70 atm. Powder and single crystal X-ray diffraction data indicate tetragonal symmetry for EuBr2 ( a = 11·574±0·006, c = 7·098±0·005 A ) and orthorhombic symmetry for EuBr3 ( a = 9·12±0·01, b = 12·66±0·02, c = 4·013±0·005 A ). Monoclinic EuBr3·6 H2O ( a = 10·025±0·008, b = 6·757±0·005, c = 8·164±0·007 A , β = 93·48±0·06° ) and orthorhombic EuBr2·H2O ( a = 11·46±0·02, b = 4·291±0·005, c = 9·20±0·01 A ) have also been characterized. Observed and calculated X-ray diffraction powder intensities for the dibromide structure are presented and discussed.