dibarium-tritin-hexaantimonide

Description

A Zintl phase, dibarium-tritin-hexaantimonide, Ba₂Sn₃Sb₆ has been synthesized, and its structure has been determined by single-crystal XRD methods. It crystallizes in the orthorhombic space groupdPnma with a = 13.351(1)? , b=4.4100(5)? , c=24.449(3) ? , and Z=4 (T=-50°C). The structure of Ba₂Sn₃Sb₆ comprises large channels [010] defined by 30-membered rings constructed from an anionic framework. This framework is built up from Sn-centered trigonal pyramids and tetrahedra, as well as zigzag chains of Sb atoms. Within the channels reside the Ba2t cations and additional isolated zigzag Sb–Sb chains. The simultaneous presence of Sn trigonal pyramids and tetrahedra implies that Ba₂Sn₃Sb₆ is a mixed-valence compound whose oxidation state notation can be best represented as (Ba^2þ)₂[(Sn^II)₂(Sn^IV)(Sb ^III)₃(Sb ^I)]₂ [(Sb ^I)₂]₂ .