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

The reactions of the Zintl phase K 2 Cs 2 Sn 9 with elemental tellurium and selenium in ethylenediamine have been investigated. From the reaction of K 2 Cs 2 Sn 9 with elemental tellurium [K‐(2,2,2‐crypt)] 4 Te 6 Te 4 ( 2 ) and [K‐(2,2,2‐crypt)] 2 Sn 2 Te 3 ( 3 ) were obtained, whereas the reaction of K 2 Cs 2 Sn 9 with elemental selenium led to the formation of [K‐(2,2,2‐crypt)] 2 Sn(Se 4 ) 3 ( 4 ) and [K‐(2,2,2‐crypt)] 2 Cs 2 Sn 2 Se 6 ·2en ( 5 ) 1) . Compounds 2 , 4 , 5 have been characterized by single crystal X‐ray structure determination.