Redetermination of the crystal structure of catena-poly[[[bis­(ethyl­enedi­amine)­platinum(II)]-μ-iodido-[bis­(ethyl­enedi­amine)­platinum(IV)]-μ-iodido] tetra­kis­(octane-1-sulfonate) dihydrate]

摘要

The structure of the title compound, which represents a mixed-valence platinum(II,IV) complex, {[PtIIPtIVI2(C2H8N2)4][CH3(CH2)7SO3]4·2H2O}n, has been redetermined in a different space group. In contrast to the previously reported determination in the space group P21cn [Matsushita & Taira (1999). Synth. Met. 102, 1787–1788], the current model was refined in the centrosymmetric space group Pmcn using the original diffraction data. The title compound has a linear chain structure composed of square-planar [Pt(en)2]2+ and elongated octa­hedral trans-[PtI2(en)2]2+ cations (en is ethyl­enedi­amine) stacked alternately, bridged by the I atoms, parallel to the c axis. Inorganic layers aligned parallel to the bc plane, composed of the Pt-complex columns, the –SO3− part of the octane-1-sulfonate anion, and the water mol­ecule of crystallization, are stacked alternately with organic layers composed of the long-chain alkyl groups along the a axis. The Pt and I sites are located on the same mirror plane whereby the I site is equally disordered over two positions. The Pt and I atoms form a slight zigzag ⋯I—PtIV—I⋯PtII⋯ chain, with PtIV—I bond lengths of 2.6888 (17) and 2.7239 (17) Å, PtII⋯I contacts of 3.2065 (17) and 3.1732 (16) Å, and PtIV—I⋯PtII angles of 178.3 (3) and 176.7 (2)°. The mixed-valence state of the Pt site is expressed by the structural parameter δ = (PtIV—I)/(PtII⋯I), with values of 0.839 and 0.858 for the two independent I atoms. In the crystal, N—H⋯O hydrogen bonds involving the cationic chains, the sulfonate groups and water mol­ecules of crystallization, stabilize the columnar structure.