The three new quaternary actinide chalcogenides Ba2TiUTe7, Ba2CrUTe7, and Ba2CrThTe7 have been synthesized. From single-crystal X-ray diffraction studies these isostructural compounds are found to crystallize in a new structure type in space group D2h16-Pnma of the orthorhombic system. The structure features ∞1[MAnTe74-] strips (M = Cr or Ti; An = Th or U) that propagate in the b-direction and are separated by Ba cations. An atoms are coordinated to eight Te atoms in a bicapped trigonal-prismatic geometry while M atoms are octahedrally coordinated to six Te atoms. Sharing of the AnTe8 and MTe6 polyhedra forms ∞1[MAnTe74-] strips. The presence of the infinite linear Te-Te-Te chains in these compounds makes assignment of oxidation states arbitrary. Resistivity measurements and DFT calculations provide further insight into the properties of these compounds.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry