Novel lanthanoid thioantimonates: the first coexistence of different types of thioantimonate anions in the same framework.

Two novel lanthanoid thioantimonates [Sm(4)(tepa)(4)(μ-η(2),η(3)-Sb(3)S(7))(2)(μ-Sb(2)S(4))] (1, tepa = tetraethylenepentamine) and [Eu(2)(tepa)(2)(μ-SbS(3))(μ-OH)](2)(SbS(4))(OH)·H(2)O (2) were solvothermally synthesized. Compound 1 represents the only example of different types of [Sb(3)S(7)](5-) and [Sb(2)S(4)](2-) anions coexisting in the same lanthanoid thioantimonate framework, while 2 displays rare mixed-valent Sb(3+)/Sb(5+) character with the Sb(3+) in a noncondensed pyramid [Sb(III)S(3)](3-). The theoretical band structure and luminescence properties have also been investigated.