Preparation and characterization of catena-[bromo(tetrahydrofuran-O)(2-thioxo-1,3-dithiole-4,5- dithiolato)antimony(III)], [Br(THF)Sb(dmit)]n

Reaction of SbBr3 with Me2Sn(dmit) (1:1 mol ratio) in Me2CO produces unsolvated [SbBr(dmit)]n, which on crystallization from THF solution gives the title compound, [SbBr(dmit)(THF)]n (5) [dmit = 2-thioxo-1,3-dithiole-4,5-dithiolato]. Taking into account the lone pair on Sb, the geometry at Sb is pseudopentagonal bipyramidal, with intramolecular bonds, Sb–Br 2.5833(3) Å, Sb–Sthiolato, of the chelating dmit ligand, 2.4723(7) and 2.4936(6) Å, Sb–O of the monodentate THF ligand 2.658(2) Å and intermolecular bonds, Sb–Sthioxo [3.2466(7) and 3.2522(8) Å] of two other dmit ligands. The intermolecular Sb–S bonds link the molecules into pairs of chains, which are further reinforced by π–π interactions involving the dmit ligands. There are no significant interactions between the chain pairs. Each dmit ligand acts as a μ3 bridge linking three different Sb atoms, with one bidentate (chelating) mode of bonding and two monodentate interactions.