Structural studies of precursor and partially oxidized conducting complexes. 20. A reduction in platinum-chain dimerization in rubidium tetracyanoplatinate chloride (2:1:0. 3) trihydrate, Rb/sub 2/(Pt(CN)/sub 4/)Cl/sub 0/ /sub 3/. 3. 0 H/sub 2/O, at 110 K as revealed by a neutron diffraction study

Journal Article · Sun Jul 01 04:00:00 EDT 1979 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic50197a040· OSTI ID:6063598

Brown, R K; Williams, J M

The crystal and molecular structure of the partially oxidized tetracyanoplatinate (POTCP) complex Rb/sub 2/(Pt(CN)/sub 4/)Cl/sub 0/ /sub 3/ . 3 H/sub 2/O has been studied at low temperature (T = 110 K) to determine if the degree of Pt-chain dimerization observed at 298 K remains constant. Crystals of the complex are tetragonal (space group P4mm) with unit cell dimensions a = 10.104 (4) A, c = 5.743 (2) A, and V/sub c/ = 586.3 A/sup 3/ for Z = 2. A 1.74% decrease in cell volume was observed upon cooling from 298 to 110 K. For the derivation of very high-precision structural parameters, a replicate data set of 1183 reflections was collected and averaged to yield 586 independent data of which 539 had F/sub 0//sup 2/) > sigma(F/sub 0//sup 2/). The structure was refined by full-matrix least-squares techniques to final R(F/sub 0//sup 2/) and R/sub w/(F/sub 0//sup 2/) values of 0.056 and 0.077, respectively. A decrease in both the average Pt--Pt spacing (approx. 0.2 A to 2.87 A) and, unexpectedly, the degree of dimerization (Pt--Pt(110 K) = 2.862 (6) and 2.885 (6) A vs 2.877 (8) and 2.924 (8) A at 298 K) is observed at 110 K. However, the electrical conductivity of this complex, which might be expected to increase with decreased Pt-chain dimerization, falls off rapidly with decreasing temperature. These seemingly contradictory observations are discussed, and the temperature-dependent electrical conductivity is interpreted within the framework of a Peierls metal-insulator transition. We also present a new interpretation of the possible correlation between the degree of partial oxidation (DPO) of the platinum atoms in POTCP salts and the presence of Pt--Pt intrachain dimerization. 3 figures, 1 table.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 6063598
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 18:7; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPLEXES
CHEMICAL REACTIONS
COHERENT SCATTERING
COMPLEXES
CRYSTAL STRUCTURE
DELAYED PROTON PRECURSORS
DIFFRACTION
DIMERIZATION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ISOTOPES
LOW TEMPERATURE
MEDIUM TEMPERATURE
MOLECULAR STRUCTURE
NEUTRON DIFFRACTION
PHYSICAL PROPERTIES
PLATINUM COMPLEXES
POLYMERIZATION
RADIOISOTOPES
REDUCTION
RUBIDIUM COMPLEXES
SCATTERING
STRUCTURAL CHEMICAL ANALYSIS
TRANSITION ELEMENT COMPLEXES