Synthesis and crystal structure of Sr 2As 2O 7 from single-crystal data

Abstract

The title compound, strontium diarseniate Sr 2As 2O 7, was prepared by solid-state method. This compound crystallizes in the tetragonal system, space group P4 1 with a 7.142 (5) Å; c 25.693 (5) Å and Z 8. Its structure is composed of SrO 7-9 polyhedra and [As 2O 7] bitetrahedral units. These groups are linked together by corner and edge-sharing forming a three dimensional framework. The crystal structure of the title compound has been the subject of a previous investigation based on X-ray powder data [M. Weil, T. dordevic, C. L. Lengauer, U. Kolitsch Solid State Sciences 11 (2009), 2111-2117]. The present investigation confirms the previous study, but with higher precision and with all displacement parameters refined anisotropically. Sr 2As 2O 7 is isotypic with the high-temperature polymorphs of Ca 2P 2O 7 and Sr 2V 2O 7. © Published under licence by IOP Publishing Ltd.