Synthèse et structure cristalline d’un matériau noir AgMnII 3(MnIII 0,26Al0,74)(MoO4)5

A new silver aluminium trimangan-ese penta-molybdate {silver(I) trimanganese(II) aluminium penta-kis-[tetra-oxidomolybdate(VI)]}, AgMn(II) 3(Mn(III) 0,26Al0,74)(MoO4)5, has been synthesized using solid-state methods. The structure is composed of M 2O10 dimers, M 3O14 (M = Mn, Al) trimers and MoO4 tetra-hedra sharing corners and forming three types of layers A, B and B'. The sequence of the constituting layers is A-BB'-A-BB', with B' obtained from B by inversion symmetry, forming a three-dimensional structure with large channels in which the positionally disordered and partially occupied Ag(+) ions reside. The Mn(III) and Al(III) atoms share the same site, M. AgMn(II) 3(Mn(III) 0,26Al0,74)(MoO4)5 is isotypic with the NaMg3 X(MoO4)5 (X = Al, In) family and with NaFe4(MoO4)5. A comparative structural description is provided between the structure of the title compound and those of related phases containing dimers, trimers and tetra-mers.