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

The asymmetric unit of the title compound {(C6H18N2)2[Sb2Br10]·H2O}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 [SbBr6]3−anion and one bisphenoidal [SbBr4]− anion in general positions. The [SbBr6]3− and [SbBr4]− anions are linked together by two long Sb—Br bonds of 3.2709 (8) and 3.5447 (7) Å into {[Sb2Br10]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 {[Sb2Br10]4−}n polymeric anions by weak N—H ...Br and O(water)—H ...Br hydrogen bonding