C4H4N4O2Pt, monoclinic, C12/c1 (no. 15), a = 10.867(1) A, b = 6.5314(6) A, c = 11.706(1) A, = 94.029(2)°, V = 828.8 A, Z = 4, Rgt(F) = 0.019, wRref(F) = 0.052, T = 293 K. Source of material An excess of diluted sulfuric acid and some drops of H2O2 solutionwere added to an aqueous solution of K2Pt(CN)4 · 3H2O. The latter was obtained by the reaction of K2PtCl4 (Alfa-Aesar, 99,9 %) and KCN (Sigma-Aldrich, 97 %) as described previously [1]. The solution was slowly evaporated at room temperature and transparent crystals with a pale brown colour of the fully oxidized [Pt(CN)4 · 2H2O] were obtained, besides colorless crystals of KHSO4 and a yellow, amorphous residue which could not be identified yet. If only small amounts of H2SO4 and H2O2 are added, bronze needles of the partially oxidized K1.75[Pt(CN)4] · 1.5H2O form [2]. Discussion In monoclinic Pt(CN)4 · 2H2O the Pt—C distances of 2.010A, in good agreement with the literature [3,4], are similar to the short Pt—O distances of 2.017 A. Therefore the platinum is octahedrally coordinated by four cyanide ligands and two oxygen atoms of the water molecules. This arrangement is similar to the potassium tetracyanoplatinate halogenides K2[Pt(CN)4X2] (X = Cl, Br, I) [5] with the water molecules replacing the halogene atoms. The Pt atoms, as the center of the octahedra, are forming a face centered arrangement, and the Pt(CN)4 · 2H2Ooctahedra are linked to each other by hydrogen bonds between the nitrogen atoms and the H2Omolecules of neighbouring complexes forming a 3D network, with N—H distances of 1.713 and 1.743A and the N$H···O distances of 2.631 and 2.602 A. Z. Kristallogr. NCS 224 (2009) 9-10 / DOI 10.1524/ncrs.2009.0006 9 © by Oldenbourg Wissenschaftsverlag, Munchen Crystal: colorless block, size 0.15 × 0.30 × 0.70 mm Wavelength: Mo K0 radiation (0.71073 A) %: 168.88 cm Diffractometer, scan mode: SMART APEX, Bruker AXS, 2 2max: 69.14° N(hkl)measured, N(hkl)unique: 5955, 1688 Criterion for Iobs, N(hkl)gt: Iobs > 2 !(Iobs), 1229 N(param)refined: 61 Programs: SHELXS-97 [6], SHELXL-97 [7], ATOMS [8] Table 1. Data collection and handling. H(1) 8f 0.040(6) 0.215(6) 0.565(5) 0.05(2) H(2) 8f 0.131(5) 0.063(6) 0.630(4) 0.09(2) Table 2. Atomic coordinates and displacement parameters (in A). Atom Site x y z Uiso _____________ * Correspondence author (e-mail: M.Jansen@fkf.mpg.de) Unauthenticated Download Date | 9/19/15 8:23 PM