Synthesis and crystal structure of a new magnesium phosphate Na3RbMg7(PO4)6

Abstract

A new magnesium phosphate, Na3RbMg7(PO4)6 [trisodium rubidium heptamagnesium hexakis(orthophosphate)], has been synthesized as single crystals by the flux method and exhibits a new structure type. Its original structure is built up from MgO x (x = 5 and 6) polyhedra linked directly to each other through common corners or edges and reinforced by corner-sharing with PO4 tetrahedra. The resulting anionic three-dimensional framework leads to the formation of channels along the [010] direction, in which the Na+ cations are located, while the Rb+ cations are located in large interstitial cavities.