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

Abstract

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 groupP21cn[Matsushita & Taira (1999).Synth. Met.102, 1787–1788], the current model was refined in the centrosymmetric space groupPmcnusing the original diffraction data. The title compound has a linear chain structure composed of square-planar [Pt(en)2]2+and elongated octahedraltrans-[PtI2(en)2]2+cations (en is ethylenediamine) stacked alternately, bridged by the I atoms, parallel to thecaxis. Inorganic layers aligned parallel to thebcplane, 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 theaaxis. 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...PtIIangles 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.