Between Elemental Match and Mismatch: From K12 Ge3.5 Sb6 to Salts of (Ge2 Sb2 )2- , (Ge4 Sb12 )4- , and (Ge4 Sb14 )4

• Published in: Angewandte Chemie International Edition 2022-10, Vol.61 (41), p.e202207232
• Main Authors: Beuthert, Katrin, Pan, Fuxing, Guggolz, Lukas, Wilson, Robert J, Hempelmann, Jan, Dronskowski, Richard, Dehnen, Stefanie
• Format: Article
• Language: English
• ISSN: 1521-3773; 1521-3773
• DOI: 10.1002/anie.202207232

The solid mixture "K2 GeSb" was shown to comprise single-crystalline K12 Ge3.5 Sb6 (1), a double salt of K5 [GeSb3 ] with carbonate-like [GeSb3 ]5- anions, and the metallic Zintl phase K2 Ge1.5 . 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: (Ge2 Sb2 )2- (in 2), (Ge4 Sb12 )4- (in 3), and in the presence of [AuMePPh3 ] also (Ge4 Sb14 )4- (in 4). The anion in 2 represents a predicted, yet heretofore missing pseudo-tetrahedral anion. 4 comprises a cluster analogous to (Ge4 Bi14 )4- and (Ga2 Bi16 )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.The solid mixture "K2 GeSb" was shown to comprise single-crystalline K12 Ge3.5 Sb6 (1), a double salt of K5 [GeSb3 ] with carbonate-like [GeSb3 ]5- anions, and the metallic Zintl phase K2 Ge1.5 . 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: (Ge2 Sb2 )2- (in 2), (Ge4 Sb12 )4- (in 3), and in the presence of [AuMePPh3 ] also (Ge4 Sb14 )4- (in 4). The anion in 2 represents a predicted, yet heretofore missing pseudo-tetrahedral anion. 4 comprises a cluster analogous to (Ge4 Bi14 )4- and (Ga2 Bi16 )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.