Proton induced reduction of WO42− under sulfide-polysulfide environment: A new route to the synthesis of complexes containing {W2VS2(μ-S)2}2+, {W2O2(μ-S)2}2+ and {W2O2(μ-S)}6+ cores

Two polymorphs of tetraethylammonium [hydrogen tris(3,5-dimethylpyrazolyl)borato]di-μ2-sulfido-disulfido(η(2)-tetrasulfido)ditungsten(V) with Z' = 1 and 2

Two polymorphs of the title compound, (C(8)H(20)N)[W(2)S(4)(S(4))(C(15)H(22)BN(6))], have been obtained unexpectedly by attempted recrystallization of a mixed-metal-sulfur cluster complex from different solvents. The dinuclear complex anion contains W(V) in two different coordination environments, one of them distorted octahedral with a tris(pyrazolyl)borate anion, a terminal sulfide and two bridging sulfide ligands, the other distorted square-pyramidal with a terminal sulfide, two bridging sulfide and a chelating tetrasulfide ligand. The three independent anions in the two polymorphs have essentially the same geometry. The central W(2)S(2) ring is a slightly folded rhombus with acute angles at the S atoms, and the WS(4) chelate ring is an envelope with one noncoordinating S atom as the flap. The second polymorph, with Z' = 2 and pseudo-inversion symmetry relating the anions of the asymmetric unit, also displays pseudo-translation features in its layer structure, and all examined crystals were found to be twinned, possibly as a consequence of this structural feature.