Crystal structure of alluaudite-type NaMg3(HPO4)2(PO4)

Ahmed Ould Saleck (1, 2) , Abderrazzak Assani (1) , Mohamed Saadi (1) , Cyrille Albert-Mercier (2) , Claudine Follet-Houttemane (2) , Lahcen El Ammari (1)

1 Laboratoire de Chimie du Solide Appliquée, Département de Chimie, Faculté des Sciences
2 LMCPA - Laboratoire des Matériaux Céramiques et Procédés Associés - EA 2443

The title compound, sodium trimagnesium bis­(hydrogen phosphate) phosphate, was obtained under hydro­thermal conditions. In the crystal, two types of [MgO6] octa­hedra, one with point group symmetry 2, share edges to build chains extending parallel to [10-1]. These chains are linked together by two kinds of phosphate tetra­hedra, HPO4 and PO4, the latter with point group symmetry 2. The three-dimensional framework delimits two different types of channels extending along [001]. One channel hosts the Na+ cations (site symmetry 2) surrounded by eight O atoms, with Na—O bond lengths varying between 2.2974 (13) and 2.922 (2) Å. The OH group of the HPO4 tetra­hedron points into the other type of channel and exhibits a strong hydrogen bond to an O atom of the PO4 tetra­hedron on the opposite side.

Mots clés: crystal structure; transition metal phosphates; alluaudite structure type; hydro­thermal synthesis; hydrogen bonding

Domaines: Matériaux

Ahmed Ould Saleck, Abderrazzak Assani, Mohamed Saadi, Cyrille Albert-Mercier, Claudine Follet-Houttemane, et al.. Crystal structure of alluaudite-type NaMg3(HPO4)2(PO4). Acta crystallographica Section E : Crystallographic communications [2015-..], 2015, 71 (7), pp.813-815. ⟨10.1107/S205698901501155X⟩. ⟨hal-03116322⟩