Single crystals of the new Zintl phases AIn2P2 [A = Ca (calcium indium phosphide), Sr (strontium indium phosphide) and Ba (barium indium phosphide)] have been synthesized from a reactive indium flux. CaIn 2P2 and SrIn2P2 are isostructural with EuIn2P2 and crystallize in the space group P6 3/mmc. The alkaline earth cations A are located at a site with m symmetry; In and P are located at sites with 3m symmetry. The structure type consists of layers of A 2+ cations separated by [In2P 2]2- anions that contain [In2P6] eclipsed ethane-like units that are further connected by shared P atoms. This yields a double layer of six-membered rings in which the In - In bonds are parallel to the c axis and to one another. BaIn2P2 crystallizes in a new structure type in the space group P21/m with Z = 4, with all atoms residing on sites of mirror symmetry. The structure contains layers of Ba2+ cations separated by [In2P2]2- layers of staggered [In2P6] units that form a mixture of four-, five- and six-membered rings. As a consequence of this more complicated layered structure, both the steric and electronic requirements of the large Ba2+ cation are met.
|Original language||English (US)|
|Journal||Acta Crystallographica Section C: Crystal Structure Communications|
|State||Published - 2009|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)