Translational Symmetries in the Linear-Chain Semiconductors K4[Pt2(P2O5H2)4X]•nH2O (X = Cl, Br, I)
The solid-state structures of the linear-chain semiconductors K4[Pt2(P2O5H2)4X]•nH2O (X = Cl, Br, I), abbreviated Pt2Cl, Pt2Br, and Pt2I, have been studied. The X-ray crystal structures of Pt2Cl at 300 and 22 K and of Pt2Br at 19 K are reported. These structures show that Pt2Cl is a composite of alternating units of Pt2 and Pt2Cl2 with (AABCCB)n translational symmetry. The X-ray structure of Pt2Br, on the other hand, shows equivalent Pt-Pt bonds and two slightly different Pt-Br bonds. Raman data confirm the composite Pt2/Pt2Cl2 structure for Pt2Cl and indicate that the Pt2Br species is comprised of dimeric units with nearly equal Pt-Pt bonds. The Pt2Br structure is viewed as involving a slight distortion from idealized (AAB)n toward (AABCCB)n translational symmetry. Structural studies of Pt2I were attempted; however, all crystals were twinned. Magnetic susceptibility, microwave conductivity, ESCA, and reflectance spectroscopy measurements are reported for Pt2Br; the material is a semiconductor, with a = 10-3Ω-1 cm-1 at 300 K, a bandgap of 0.08 eV, and a bandwidth greater than 0.05 eV. © 1988, American Chemical Society. All rights reserved.
Publication Source (Journal or Book title)
Journal of the American Chemical Society
Butler, L., Swanson, B., Zietlow, M., Schaefer, W., Gray, H., Che, C., Sridhar, S., & Clark, R. (1988). Translational Symmetries in the Linear-Chain Semiconductors K4[Pt2(P2O5H2)4X]•nH2O (X = Cl, Br, I). Journal of the American Chemical Society, 110 (4), 1155-1162. https://doi.org/10.1021/ja00212a025