Na5(NH4)Mn3[B9P6O33(OH)3]·1.5H2O

Abstract

The overall hexagonal framework of the title compound, pentasodium ammonium trimanganese(II) borophosphate sesquihydrate, consists of tube-like borophosphate anions, ∞1{[B3P2O11(OH)]4−}, made up of corner-sharing PO4 and BO4 tetrahedra and BO2(OH) triangles, forming ten-membered ring windows. The tubes are interconnected via distorted MnO6 octahedra, establishing a three-dimensional open-framework structure with two different types of ring-channels (12- and six-membered) that run along [001]. The 12-membered ring channels are occupied by NH4+ ions and water molecules. The ten-membered ring windows in the walls of the tubes are occupied by Na+ ions. The remaining Na+ ions and the water molecules, one of which is half-occupied, reside within the six-membered ring channels. The structural setup is consolidated by an O—H...O hydrogen bond between the OH group and an opposite O atom of the framework. Donor–acceptor distances ranging from 2.80 to 3.35 Å between the ammonium N atom, water O atoms and framework O atoms indicate further hydrogen-bonding interactions.