catena-Poly[N,N,N′,N′-tetra­methyl­ethylendi­ammonium [[tetra­bromido­antimonate(III)]-μ-bromido] hemihydrate]

The asymmetric unit of the title compound {(C(6)H(18)N(2))(2)[Sb(2)Br(10)]·H(2)O}(n), consists of two tetra­methyl­ethylendi­ammonium cations that are located on centres of inversion, as well as one tetra­methyl­ethylendi­ammonium cation, one water mol­ecule, one distorted octahedral [SbBr(6)](3−)anion and one bisphenoidal [SbBr(4)](−) anion in general positions. The [SbBr(6)](3−) and [SbBr(4)](−) anions are linked together by two long Sb—Br bonds of 3.2709 (8) and 3.5447 (7) Å into {[Sb(2)Br(10)](4−)}(n) chains along [001]. One of the three tetra­methyl­ethylendi­ammonium cations is disordered and was refined using a split model (occupancy ratio 0.58:0.42). The cations and the water mol­ecule are connected to the {[Sb(2)Br(10)](4−)}(n) polymeric anions by weak N—H ⋯Br and O(water)—H ⋯Br hydrogen bonding.