Synthesis and Structure of the Zintl Phase SrSn(3)Sb(4).

The new Zintl compound strontium tin antimonide, SrSn(3)Sb(4), has been synthesized, and its structure has been determined by single-crystal X-ray diffraction methods. It crystallizes in the orthorhombic space group -Pnma with a = 10.060(2) Å, b = 4.361(1) Å, c = 22.934(4) Å, and Z = 4 at 22 degrees C. The structure of SrSn(3)Sb(4) may be described as consisting of large, narrow channels running along [010] defined by 30-membered rings constructed from an anionic framework of linked SnSb(4) tetrahedra, SnSb(3) trigonal pyramids, and zigzag Sb-Sb chains. Sr(2+) cations are situated within these channels. The channel structures of SrSn(3)Sb(4) and Ba(2)Sn(3)Sb(6) are closely related.