Syntheses and Crystal Structures of BaAgTbS 3 , BaCuGdTe 3 , BaCuTbTe 3 , BaAgTbTe 3 , and CsAgUTe 3

Five new quaternary chalcogenides of the 1113 family, namely BaAgTbS 3 , BaCuGdTe 3 , BaCuTbTe 3 , BaAgTbTe 3 , and CsAgUTe 3 , were synthesized by the reactions of the elements at 1173–1273 K. For CsAgUTe 3 CsCl flux was used. Their crystal structures were determined by single‐crystal X‐ray diffraction studies. The sulfide BaAgTbS 3 crystallizes in the BaAgErS 3 structure type in the monoclinic space group C 3 , 2 h ‐ C 2/ m , whereas the tellurides BaCuGdTe 3 , BaCuTbTe 3 , BaAgTbTe 3 , and CsAgUTe 3 crystallize in the KCuZrS 3 structure type in the orthorhombic space group D 1 ,2 7 , h ‐ Cmcm . The BaAgTbS 3 structure consists of edge‐sharing [TbS 6 9– ] octahedra and [AgS 5 9– ] trigonal pyramids. The connectivity of these polyhedra creates channels that are occupied by Ba atoms. The telluride structure features 2 ∞ [ MLn Te 3 2– ] layers for BaCuGdTe 3 , BaCuTbTe 3 , BaAgTbTe 3 , and 2 ∞ [AgUTe 3 1– ] layers for CsAgUTe 3 . These layers comprise [ M Te 4 ] tetrahedra and [ Ln Te 6 ] or [UTe 6 ] octahedra. Ba or Cs atoms separate these layers. As there are no short Q ··· Q ( Q = S or Te) interactions these compounds achieve charge balance as Ba 2+ M + Ln 3+ ( Q 2– ) 3 ( Q = S and Te) and Cs + Ag + U 4+ (Te 2– ) 3 .