Abstract: | A Contribution on CuPrMo2O8 and CuTbMo2O8 Single crystals of (I): CuPrMo2O8 and (II): CuTbMo2O8 were prepared by solid state reactions in closed copper tubes. They crystallize with orthorhombic symmetry, space group D -Pbca, (I): a = 10.4114, b = 9.8917, c = 14.8287 Å, (II): a = 10.2243, b = 9.7385, c = 14.6000, Z = 8. Both compounds are isotypic to CuYMo2O8, showing isolated MoO4 tetrahedra, square antiprismatic coordination of Ln3+ and Cu+ besides one edge of an O2? triangle. Calculations of the coulombterm of lattice energy support the oxidation state Cu2+ in combination with mixed valences of Mo6+ and Mo5+ on the molybdenum point positions. |