Polytellurides and Polyselenides - Compounds Containing $_{\infty}^{1}\rm [Te_{6}-Te_{4}]^{4-}$ and [Sn(Se4)3]2−Anions

The reactions of the Zintl phase K2Cs2Sn9 with elemental tellurium and selenium in ethylenediamine have been investigated. From the reaction of K2Cs2Sn9 with elemental tellurium [K-(2,2,2-crypt)]4Te6Te4 (2) and [K-(2,2,2-crypt)]2Sn2Te3 (3) were obtained, whereas the reaction of K2Cs2Sn9 with elemental selenium led to the formation of [K-(2,2,2-crypt)]2Sn(Se4)3 (4) and [K-(2,2,2-crypt)]2Cs2Sn2Se6·2en (5)1). Compounds 2, 4, 5 have been characterized by single crystal X-ray structure determination.