PREPARATION, CRYSTAL-STRUCTURE, AND INFRARED CHARACTERIZATION OF THE FIRST THIOCYANATO-OXY-ANTIMONATE(III) [(CH3)(4)N](2)[SB6O4(NCS)(12)]

The salt [(CH3)(4)N](2)[Sb6O4(NCS)(12)] is the first identified thiocy anato-oxy-antimonate(III) complex. Reported are details of the synthes is, relevant infrared data and its x-ray structure. The compound cryst allizes in the triclinic space group P (1) over bar with Z=2 (C10H12N7 O2S6Sb3) and unit cell dimensions a = 11.314(6), b = 12.846(3), c = 8. 679(2) Angstrom; alpha = 91.93(3)degrees, beta = 90.31(3)degrees and y = 99.13(3)degrees. It contains centrosymmetric [Sb6O4(NCS)(12)](2-) a nions packed with isolated tetramethyl-ammonium cations. The fundament al structural element of the anion is provided by the fusion of three SbOSbO rings forming a zig-zag portion of a ribbon, only slightly plea ted. Peculiar is the unequivalence of the six thiocyanate ligands, tho ugh all primarily N-bonded to antimony atoms. Three thiocyanates are t erminal while other three are asymmetrically N-bridging between two ce nters; two of this latter type are also interconnecting the anions via Sb...S contacts. There are three different antimony environments, the primary bonding at Sb being to one nitrogen and three oxygens, to one oxygen and three nitrogens and to two atoms of each type.