New double molybdates in Cs-Fe(II,III)-Mo-O system

Three new complex molybdenum oxides Cs2Fe2(MoO4)3, Cs4Fe(MoO4)3 and CsFe5(MoO4)7 with average oxidation states of Fe lower than +3 were obtained while studying the phase formation in Cs-Fe(II,III)-Mo-O system and investigated by X-ray single crystal analysis at room temperature 100K. The structure of cubic molybdate Cs2Fe2(MoO4)3 has space group P213 with parameters: a = 10.9161(2) Е, Z = 4. Hexagonal Cs4Fe(MoO4)3 crystallizes in space group P 6 2c (a = 6.2922(16) Å, c = 23.937(13) Å, Z = 2). CsFe5(MoO4)7 crystallizes in monoclinic symmetry (P21/m, a = 6.9239(6) Å, b = 21.4477(19) Å, c = 8.6374(8) Å, β= 101.667(2)° Z = 2) and represents a new structure type.