On the flexibility of thioantimonate networks:: Solvothermal syntheses and crystal structures of six new thioantimonates(III) with the [Sb4S7]2- anion

Six new thioantimonates(III) with the [Sb4S7](2-) anion were obtained Under solvothermal conditions with in-situ formed transition metal complexes as Structure directors. In the two isostructural compounds [Fe(dien)(2)]Sb4S7 center dot H2O (1) and [Co(dien)(2)]Sb4S7 center dot 0.5 H2O (2) (dien = diethylenetriamine; space group: P2(1)/c) the layered [Sb4S7](2-) anion is characterized by Sb8S8 rings with a diameter of about 9.6 center dot 7.6 angstrom. The cation complexes are located above and below the pores of the rings. Despite the larger size of the cation complex the network topology of the third thioantimonate [Ni(dien)(tren)]Sb4S7 (3) (tren = tris(2-aminoethyl)amine; space group: P2(1)/n) is similar to that of the first two compounds. In the isostructual thioantimonates [M(trien)]Sb4S7 (M = Zn (4); M = Mn (5); trien = triethylenetetramine; space group: P (l) over bar) the M2+ ions are fivefold coordinated by four N atoms of the amine molecule and by one S atom of the thioantimonate anion forming a MN4S trigonal bipyramid. Sb8S16 building blocks are the central structural motifs of the anion. Two of the terminal S atoms at the periphery of the Sb8S16 units are bound to M2+ ions and the four remaining terminal S atoms connect adjacent Sb8S16 groups into the final [Sb4S7](2-) anion which is a unique feature in the thioantimonate(111) chemistry. The NiN4S2 octahedron is severly distorted with one very long Ni-S bond of 2.782(2) angstrom. In all compounds several short S ... H distances indicate hydrogen bonding interactions.