An ethanol-solvated centrosymmetric dimer of bismuth(III) and thiosaccharinate resulting from `semicoordination'...

In the title compound, bis(μ-1,1-dioxo-1,2-benzothiazole-3-thiolato)-κ(3)N,S:S;κ(3)S:N,S-bis[(1,1-dioxo-1,2-benzothiazole-3-thiolato-κ(2)N,S)(ethanol-κO)bismuth(III)] ethanol hemisolvate, [Bi2(C7H4NO2S2)6(C2H5OH)2]·0.5C2H5OH, three independent thiosaccharinate (tsac) anions chelate the metal centre through the endocyclic N and exocyclic S atoms. The complex also presnts two `semicoordination' contacts, one from a pendant ethanol solvent molecule and a second one from an S atom of a centrosymmetrically related molecule. This latter interaction complements two π-π interactions between tsac rings to form a dimeric entity which is the elemental unit that builds up the crystal structure. These dinuclear units are connected to each other via a second type of π-π interaction, generating chains along [111]. Two ethanol molecules, one of them of full occupancy at a general position and semicoordinated to the central cation, and a second one depleted and disordered around a symmetry centre, stabilize the structure. The complex was studied theoretically and the vibrational assignations were confirmed by employing theoretical density functional theory (DFT) methods.