Synthesis and Crystal Structure of the Strontium Beryllate Sr3Be2O5

Abstract

Beryllates show an interesting and diverse structural chemistry, resembling that of well-investigated silicates. The coexistence of tetrahedral and trigonal coordination of Be by O atoms in oxoberyllates allows for an even broader variety of structural motives and implies a plurality of possible atomic ratios Be:O in ternary or higher compounds. We have now synthesized the novel strontium oxoberyllate Sr3Be2O5 via a high-temperature high-pressure reaction and have structurally characterized the ternary oxide by single-crystal and powder X-ray diffraction analysis. Sr3Be2O5, a low condensed oxoberyllate, contains unprecedented [Be2O5]6– double triangles and Sr atoms in both double-capped trigonal-prismatic and octahedral coordination. These motifs show striking resemblance to α-SrBeO2 and SrO, combining their structural properties. Lattice energy (MAPLE) calculations corroborate found parallels to the known phases SrO and α-SrBeO2.