ChemInform Abstract: Ge Pairs and Sb Ribbons in Rare‐Earth Germanium Antimonides Ln₁₂Ge_7‐xSb₂₁ (Ln: La—Pr).

Abstract

are synthesized from the elements (800°C, 12 d) and characterized by single crystal XRD, magnetic measurements, and TB-LMTO band structure calculations. The compounds crystallize with a new structure type in the orthorhombic space group Immm with Z = 2. The three-dimensional polyanionic frameworks consist of Ge pairs and Sb ribbons forming large channels occupied by columns of face-sharing Ln 6 (Ln: La-Pr) trigonal prisms. These trigonal prisms are centered by additional Ge and Sb atoms to form GeSb3 trigonal-planar units. Ce12Ge6.5Sb21 shows antiferromagnetic coupling but no long-range ordering down to 2 K. -(BIE, H.; MAR*, A.; Chem.