Different Chemical Environments of [Ge4Se10]4- in the Li+ Compounds [Li4(H2O)16][Ge4Se10]·4.33H2O, [{Li4(thf)12}Ge4Se10], and [Li2(H2O)8][MnGe4Se10], and Ionic Conductivity of Underlying "Li4Ge4Se10".

The crystalline selenido germanates [Li4(H2O)16][Ge4Se10]·4.3H2O (1), [{Li4(thf)12}Ge4Se10] (2), and [Li2(H2O)8][MnGe4Se10] (3) (thf = THF = tetrahydrofuran) were obtained by an extraction of a glassy ternary phase of the nominal composition Li4Ge4Se10 (=Li2S·2GeSe2) with water (1) or THF (2) and slow evaporation of the solvent or by being layered with MnBr2 in H2O/MeOH (3), respectively. The compounds contain known selenido germanate anions, however, for the first time with Li+ counterions. This is especially remarkable for the prominent ∞3{[MnGe4Se10]2-} open-framework structure, which was reported to crystallize with (NMe4)+, Cs+, Rb+, and K+ counterions, but it has not yet been realized with the smallest alkali metal cation. Impedance spectroscopic studies on Li4Ge4Se10 classify the glassy solid as a moderate Li+ ion conductor.