Silver(I) diaqua-magnesium catena-borodiphosphate(V) monohydrate, AgMg(H2O)2[BP2O8]·H 2O

Abstract

The title compound contains infinite one-dimensional [BP2O 8]3- borophosphate helical ribbons, built up from alternate BO4 and PO4 tetra-hedra arranged around the 65 screw axes. The vertex-sharing BO4 and PO4 tetra-hedra form a spiral ribbon of four-membered rings in which BO4 and PO 4 groups alternate. The ribbons are connected through slightly distorted MgO4(H2O)2 octa-hedra, in which the four O atoms belong to the phosphate groups. The free threads of the helices are occupied by silver ions, which are in an irregular environment surrounded by six O atoms. The central channels of the helices, running along the c axis, are filled with the water mol-ecules. The structure is stabilized by O - H⋯O hydrogen bonds between the water mol-ecules and O atoms that are part of the helices. The crystal structure of the title compound is isotopic with other analogous borophosphates such as A I M II(H2O) 2[BP2O8]·H2O, where A I = Li, Na, K or NH4+ and M II = Mg, Mn, Fe, Co, Ni, Cu, Zn or Cd.