IrIn7GeO8 = [IrIn6](GeO4)(InO4) und Verbindungen der Mischkristallreihe [IrIn6](Ge1+xIn1−4x/3O8) (0 ≤ x ≤ 0.75) – erste Oxide mit [IrIn6]‐Oktaedern

IrIn7GeO8 = [IrIn6](GeO4)(InO4) and Compounds of the Solid Solution Series [IrIn6](Ge1+xIn1−4x/3O8) (0 ≤ x ≤ 0.75): First Oxides containing [IrIn6] Octahedra The low valent indiumoxides IrIn7GeO8 = [IrIn6](GeO4)(InO4) and [IrIn6](Ge1+xIn1−4x/3O8) (0 x ≤ 0.75) are formed by heating intimate mixtures of Ir, In, In2O3 and GeO2 in corundum crucibles under an atmosphere of argon (1420 K, 70 h). The compounds are black and semiconducting. X‐ray powder diffraction patterns can be indexed on the basis of a face centered cubic unit cell with lattice parameters ranging from a = 1012.3(1) pm (x = 0) to a = 1007.3(1) pm (x = 0.75). Characteristic building units in [IrIn6](Ge1+xIn1−4x/3O8) are isolated [IrIn6]9+ octahedra with short Ir‐In distances of 253.5 pm, which are linked via [GeO4]4− and [InO4]5− tetrahedra to a three dimensional framework. Starting from IrIn7GeO8 = [IrIn6](GeO4)(InO4), the isoelectronic substitution of 4 In3+ ions by 3 Ge4+ ions and one Ge‐vacancy leads to the formation of a solid solution series [IrIn6](GeO4)1+x(O4)x/3(InO4)1−4x/3, which shows a slight decrease in the cubic lattice parameter with increasing x. According to Rietveld refinements the structure of [IrIn6](GeO4)(InO4) exhibits a statistical distribution of the tetrahedrally coordinated Ge and In atoms ( , R(prof.) = 4.4 %, R(int.) = 2.5 %). The crystal and electronic structures of [IrIn6](GeO4)(InO4) are discussed on the basis of first principles electronic structure calculations.