Préparation et structure cristalline dun nouveau bis-diphosphate de bismuth et de sodium Na5Bi(P2O7)2

The pentasodium bismuth bis-diphosphate has been synthesized and characterized by single-crystal X-ray diffraction. Na5Bi (P2O7)2is triclinic (P-1) witha=9.276(3)? ,b=9.806(3)? ,c=7.272(1)? ,=77.73(2),=109.21(3),=97.92(2),V=608.71(4)?3,Z= 2. Crystal structure has been refined with a finalR(F2)=0.0167 andRw(F2)=0.0419 for 2672 reflections withF2>4(F2). The structure is built up from BiO7polyhedra and P2O7groups sharing corners and edges to form a two-dimensional framework having large windows stacked along thecdirection to form tunnels. The Na+cations are located in the interlayer space.