Two new polymorphs, beta- and gamma-In(2)Ge(6)O(15)(NH(2)CH(2)CH(2)NH(2))(2), have been synthesized under solvothermal conditions using 2-methylpentamethylenediamine as a solvent and structurally characterized by single-crystal X-ray diffraction. Both structures contain single layers with the composition [Ge(6)O(15)] that are connected by In(2)O(6)N(4) octahedral dimers to form 3D frameworks. The germanate layers contain four-, six-, and eight-membered rings and six-membered rings in the beta and gamma polymorphs, respectively. Compounds with related structures are discussed for comparison.
