Preparation and Crystal Structure of K₂Ag₁₂Te₇

Summary.

 Single crystals of K₂Ag₁₂Te₇ (a = 11.460(2), c = 4.660(1) Å; V = 530.01 ų; space group: P6₃/m; Z = 1) were synthesized under hydrothermal conditions at 250°C in concentrated aqueous KOH solution from elementary silver and tellurium. The crystal structure is characterized by trigonal prismatic KTe₆ polyhedra, connected via two common faces to KTe₃ rods parallel to [001]. These rods are combined by two crystallographically independent Ag atoms, each coordinated to four Te and three Ag atoms (Ag–Te and Ag–Ag < 3.1 Å) to a framework of the formula (K₂Ag₁₂Te₆)^2 + and with channels parallel to the sixfold axis. These channels are statistically occupied by one further Te atom per unit cell, distributed over two independent positions.