Easy Access to Soluble Polyanions—Stabilization of the One-Dimensional Chain ¹_∞[K₄Sn₉] by [18]Crown-6 in [K₄Sn₉([18]crown-6)₃]⋅ethylenediamine

Well-characterized Group 14 Zintl anions were accessible by solution methods only in low yields up to now. An easy and inexpensive reaction route to polyanions, which starts from the elements, is admissible through the usage of [18]crown-6 as reaction medium at 40°C. The [K([18]crown-6)] unit proves to be an advantageous connecting device between intermetallic and organic networks. The title compound can be regarded as a supramolecular aggregate of a one-dimensional substructure of the composition K₄Sn₉ (see picture) and an organic component.