Synthesis and Structure of New BiMn2MO6 Compounds Where M=P, As, or V

The new compounds BiMn2PO6, BiMn2AsO6, and BiMn2 VO6 have been prepared and shown to be structurally related to several other BiA2MO6 compounds. The structure of BiMn2PO6 was refined from neutron powder diffraction data in space group Pnma with a=12.04 ?, b=5.37 ?, c=8.13 ?, and Z=4. It contains (BiO2)1- chains and (PO4)3- tetrahedra. The observed fivefold coordination for the Mn2+ cations is unusual for Mn in this oxidation state.