[{(C2H5)(2)In2}2In2Ge2S8] center dot [(C2H5)(2)NH](0.25): A three-dimensional thiogermanate-indate framework based on the interconnection of [In2Ge2S6S4/2](2-) adamantane-like building units

摘要

The new compound [{(C2H5)(2)NH2}(2)In2Ge2S8](.)[(C2H5)(2)NH](0.25) was synthesized under solvothermal conditions using elemental in, Ge, and S in diethylamine. The title compound crystallizes in the orthorhombic space group Pna2(1) with a = 12.804(3)Angstrom b = 17.615(4) Angstrom, c = 13.067(3) Angstrom, V = 2947.2 Angstrom(3), and Z = 4. The structure consists of (In/Ge)S-4 tetrahedra as primary building units and four such tetrahadra are joined via common corners to form [In2Ge2S6S4/2](2-) adamantane-like building units. These building units are interconnected yielding a three-dimensional anionic tetrahedral framework resembling that of cristobalite if the adamantane-like cages are seen as supertetrahedra. Three types of channels with diameters ranging from 8.2(.)10.3 Angstrom to 8.5(.)13.1 Angstrom intersect the structure. Charge compensation is achieved by [(C2H5)(2)NH2](+) cations which are located within the voids of the anionic network. The compound decomposes in two steps yielding In2S3 and Ge as solid residue. [References: 25]