Abstract
The solid mixture "K(2) GeSb" was shown to comprise single-crystalline K(12) Ge(3.5) Sb(6) (1), a double salt of K(5) [GeSb(3) ] with carbonate-like [GeSb(3) ](5-) anions, and the metallic Zintl phase K(2) Ge(1.5) . Extraction of 1 with ethane-1,2-diamine in the presence of crypt-222 afforded [K(crypt-222)](+) salts of several novel binary Zintl anions: (Ge(2) Sb(2) )(2-) (in 2), (Ge(4) Sb(12) )(4-) (in 3), and in the presence of [AuMePPh(3) ] also (Ge(4) Sb(14) )(4-) (in 4). The anion in 2 represents a predicted, yet heretofore missing pseudo-tetrahedral anion. 4 comprises a cluster analogous to (Ge(4) Bi(14) )(4-) and (Ga(2) Bi(16) )(4-) , and thus one of the most Sb-rich binary p-block anions. The unprecedented cluster topology in 3 can be viewed as a defect-version of the one in 4 upon following a "dead end" of cluster growth. The findings indicate that Ge and Sb atoms are at the border of a well-matching and a mismatch elemental combination. We discuss the syntheses, the geometric structures, and the electronic structures of the new compounds.