Structure of Dibromo(1,2-diaminoethane)palladium(IV)-bis(1,2-diaminoethane)- palladium(II) Tetrakisperchlorate, [Pd(en)₂Br₂][Pd(en)₂](ClO₄)₄

Abstract

<jats:p>Orthorhombic [Pd(C<jats:sub>2</jats:sub>H<jats:sub>8</jats:sub>N<jats:sub>2</jats:sub>)<jats:sub>2</jats:sub>Br<jats:sub>2</jats:sub>][Pd(C<jats:sub>2</jats:sub>H<jats:sub>8</jats:sub>N<jats:sub>2</jats:sub>)][ClO<jats:sub>4</jats:sub>]<jats:sub>4</jats:sub>, C<jats:sub>8</jats:sub>H<jats:sub>32</jats:sub>Br<jats:sub>2</jats:sub>Cl<jats:sub>4</jats:sub>N<jats:sub>8</jats:sub>O<jats:sub>16</jats:sub>Pd<jats:sub>2</jats:sub>, M<jats:sub>r</jats:sub> = 890.42, crystallizes in space group Iba2, a = 9.651(2), b = 13.951(8), c = 10.771(2) Å, Z = 2, V = 1412.80 Å<jats:sup>3</jats:sup>, d<jats:sub>c</jats:sub> = 2.05 g cm<jats:sup>-3</jats:sup>, R = 0.0564 for 1545 unique reflections. Data collection: MoK<jats:sub>α</jats:sub>, λ = 0.71069 Å, room temperature.</jats:p><jats:p>The structure is a typical Wolffram’s Salt Analogue (WSA) with infinite stacks of planar [Pd(en)<jats:sub>2</jats:sub>]<jats:sup>2+,4+</jats:sup> complex cations bridged by bromides. The ligands are three-dimensionally ordered. Intra-chain and inter-chain hydrogen bridges link the ligands with the perchlorate counter ions which occupy statistically two different orientations. Diffuse sheets appear together with Bragg reflections for 1 odd layers indicating a thermally activated motion of the bromides in chain direction. This model was confirmed with temperature dependent Weissenberg work </jats:p>

Mixed-valence linear-chain complexes: X-ray structural characterization of a PdII/PdIVBr2 chain and of three mixed-metal chains, [NiPt(en)4Cl2]4+, [PdPt(pn)4Cl2]4+ and [NiPt(pn)4Cl2]4+, all as perchlorate salts

“…It is pertinent to note that our investigations have given results for complexes (1) and (2) which are ir agreement with those of Martin et al (1985) in their determination of structure (1), with clear indications that space group Iba2 is correct. Refinement in this space group gave R, R w values of 0.039, 0.051 for complex (1) [Martin et al (1985) obtained 0.048, 0.056 for a comparable data set] and 0.32, 0.045 for complex (2).…”

“…Recent spectroscopic studies have pointed to the existence of analogous palladium mixed-valence complexes and also of mixed-metal complexes of the sort [M(LL) (Clark, Croud & Wills, 1988;Clark & Croud, 1985, 1986 (Beauchamp, Layek & Theophanides, 1982) whilst the structure of the corresponding bromide, our compound (1), was reported whilst our work was in progress (Martin, Keller & Muller, 1985). This paper is concerned with the characterization of three mixed-metal complexes, (3) and [Ni(pn)2][Pt(pn)2C12](CIO4) 4 (4).…”

“…Refinement in this space group gave R, R w values of 0.039, 0.051 for complex (1) [Martin et al (1985) obtained 0.048, 0.056 for a comparable data set] and 0.32, 0.045 for complex (2). In the latter complex the metal site was represented by equal proportions of Pt and Ni, which were also tied to a single set of displacement-factor coefficients.…”

MX-Chain Compounds with ReO4 Counterions: Exploration of the Robin–Day Class I–II Boundary

“… a d value is defined as d ≡ { l 1 (M II ···X) – l 2 (M IV –X)}/ L (M··M). b Reference . c Reference . d Reference . e Reference (orthorhombic phase). f Reference . …”