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The P43 enanti-omorph of Sr2As2O7
Aicha Mbarek1, Fadhila Edhokkar2
1Laboratoire de Chimie Industrielle, Département de Génie des Matériaux, Ecole Nationale d'Ingénieurs de Sfax Université de Sfax, BP W3038, Sfax, Tunisia.
Acta Crystallographica. Section E, Structure Reports Online
|January 24, 2014
Summary
Strontium diarsenate (Sr2As2O7) crystal structure was re-examined. The study identified the P43 enantiomorph, differing from previous P41 space group assignments for this inorganic compound.
Area of Science:
- Solid-state chemistry
- Crystallography
- Materials science
Background:
- Previous studies determined the strontium diarsenate (Sr2As2O7) structure in the P41 space group.
- Isotypic A2B2O7 compounds typically crystallize in the P41 space group.
Purpose of the Study:
- To reinvestigate the crystal structure of strontium diarsenate (Sr2As2O7).
- To clarify the correct space group and enantiomorph of Sr2As2O7.
Main Methods:
- Single-crystal X-ray diffraction analysis.
- Crystal structure determination and refinement.
Main Results:
- The redetermination revealed Sr2As2O7 crystallizes in the P43 space group, the enantiomorph of the previously reported P41.
- The structure exhibits two eclipsed diarsenate (As2O7) groups with distinct As-O bond lengths.
- Four strontium (Sr2+) sites were identified with coordination numbers from seven to nine.
- Building units are arranged in sheets parallel to the (001) plane.
Conclusions:
- The correct space group for strontium diarsenate is P43, not P41 as previously reported.
- This finding corrects the crystallographic understanding of Sr2As2O7 and related A2B2O7 compounds.
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