Structural studies of precursor and partially oxidized conducting complexes. 21. Single-crystal and powder time-of-flight neutron diffraction studies of Tl/sub 4/(Pt(CN)/sub 4/)CO/sub 3/

Journal Article · Mon Jun 01 04:00:00 EDT 1981 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic50220a039· OSTI ID:6455941

Beno, M A; Rotella, F J; Jorgensen, J D; Williams, J M

The crystal and molecular structure of the unusual complex Tl/sub 4/(Pt(CN)/sub 4/)CO/sub 3/, obtained by mixing Tl/sub 2/(Pt(CN)/sub 4/) and Tl/sub 2/CO/sub 3/ in aqueous solution at 95/sup 0/C, was determined by both single-crystal and time-of-flight powder neutron diffraction. The complex is not a partially oxidized tetracyanoplatinate (POTCP) salt and contains Pt in an integral (2.0) oxidation state. The lustrous metallic green complex crystallizes in the tetragonal space group, with unit cell constants a = b = 9.911 (4) A (9.908 (3) A, powder study), c = 6.490 (3) A (6.487 (2) A), and V/sub c/ = 637.5 A/sup 3/ at 298/sup 0/K. In the single-crystal study diffracted intensities of 267 independent reflections were measured to a (sin theta)/lambda limit of 0.438 A/sup -1/, and of these 202 had F/sub 0//sup 2/ > sigma(F/sub 0//sup 2/). Full-matrix least-squares refinement of all structural parameters resulted in a final R(F/sub 0//sup 2/) = 0.075 (all data) and R(F/sub 0//sup 2/) = 0.068. It is important to note that the structural parameters derived with use of the time-of-flight neutron diffraction and single-crystal methods are, in this case, virtually identical. The most pertinent structural feature in Tl/sub 4/(Pt(CN)/sub 4/)CO/sub 3/ is that the Pt atoms form perfectly linear chains with Pt-Pt separations crystallographically constrained to a value of (c/2) = 3.245 (3) A. The intrachain Pt-Pt separation is much longer than in the partially oxidized salts (2.80 to 2.96 A) and accounts for the low electrical conductivity in this salt. The structure is composed of square-planar Pt(CN)/sub 4//sup 2 -/ groups linked by Tl/sup +/ cations, all of whichoccupy the same molecular plane, and carbonate groups which lie between the Pt(CN)/sub 4//sup 2 -/ groups. The CO/sub 3//sup 2 -/ group oxygen atoms are clearly disordered among at least two positions, creating six partially occupied oxygen atom sites per group. The Tl/sup +/ and O separations are approx. 0.2 A shorter than the sum of the ionic radii which is probably an artifact of disorder.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 6455941
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 20:6; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBON COMPOUNDS
CARBONATES
COHERENT SCATTERING
COMPLEXES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CYANIDES
DIFFRACTION
MEDIUM TEMPERATURE
MOLECULAR STRUCTURE
NEUTRON DIFFRACTION
OXYGEN COMPOUNDS
PLATINUM COMPLEXES
SCATTERING
SYNTHESIS
TETRAGONAL LATTICES
THALLIUM COMPOUNDS
TRANSITION ELEMENT COMPLEXES
X-RAY DIFFRACTION