Abstract: | Bis(disulfide)bridged Nb(+4) cluster halide complexes Nb2S4X8]4– (X = Cl, Br) were prepared by acid hydrolysis of Nb2S4(NCS)8]4– in concentrated aqueous HCl or HBr, solution from which they can be isolated as double salts Cs5Nb2S4X8]X (X = Cl, 1 ; X = Br, 2 ). The crystal structures of 1 and 2 were determined. The isolation and X-ray structure of oxonium salt (H3O)5 Nb2S4Cl8]Cl ( 3 ) is also reported. 1 – 3 contain new Nb2S4X8]4– anions which can also be viewed as excised building blocks of polymeric solids NbS2X2. The extra halogen resides in the center of octahedron formed by six Cs+ or H3O+ ions. All the three salts are isostructural and crystallize in tetragonal space group Immm with the following parameters: a = 10.269(2), b = 16.343(2), c = 7.220(1) Å for 1 , a = 10.934(1), b = 16.613(2), c = 7.470(1) Å for 2 , a = 9.639(1), b = 16.031(1), c = 7.071(1) Å for 3 . The parameters of the Nb2S4 core are only slightly affected by the change from Cl to Br. |