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Deals with a study which determined the crystal structure of the copper compound. Chemical components of the copper compound; Measurement of power susceptibilities; Power susceptibility as a function of temperature of the copper analog.

The crystal structure of bis(cyclopentylammonium)tetrabromocuprate(II) has been determined at room temperature and at -70 °C. The room temperature structure is orthorhombic, space group Pn21a, with a = 12.092(6) Å, b = 8.134(4) Å, and c = 18.698(10) Å. The Iow temperature structure is also orthorhombic, space group Pna21, with a = 24.111(5) Å, b = 8.089(2) Å, and c = 18.448(4) Å. DSC studies reveal the presence of a weak endotherm at -13 °C. The structures of the two phases are very similar, differing only in the relative orientations of the cyclopentyl rings of the organic cations and slight displacements of the anionic tetrahedra. The CuBr42- anions in the Iow temperature phase are arranged to define a spin ladder system through Cu-Br···Br-Cu two-halide exchange pathways. Magnetic susceptibility data have been analyzed and yield antiferromagnetic exchange strengths 2Jrail/k = 11.6 K and 2Jrung/k = -5.5 K with a singlet-triplet gap energy Δ/kB = 2.3 K. This is the first report of a spin ladder with a stronger interaction along the axis of the ladder than along the rungs. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound (C3H12N2)2Cu2Br6, is monoclinic, space group P21/n, with lattice constants a=8.222(2), b=11.214(2), c=10.646(2) A˚, β=91.97(1)° and V=981.0(3) A˚3. The structure contains anionic Cu2Br62− dimers and N-methylethylenediammonium (henceforth MEDA2+) cations. The centrosymmetric dimer units are composed of two edge-shared CuBr4 tetrahedra, with bridging Cu–Br distances 0.08 A˚ longer than the terminal distances. A pair of MEDA2+ cations hydrogen bond to each dimer via two of the –NH3+ hydrogen atoms and one of the –NH2+- hydrogen atoms. Additional hydrogen bonding between the cations and anions tie the structure together in a complex supramolecular network. [Copyright &y& Elsevier]

The structures of three hybrid organic/inorganic halometalate salts are reported, and the layer structures developed are contrasted. Crystal structures of the isostructural N-methylethylenediammonium (MEDA²+) and N-ethylethylenediammonium (EEDA²+) salts of copper(I) bromide are both triclinic, space group P&1macr;, with lattice constants a = 6.284(7), b = 7.842(6), and c = 12.03(1) Å, α = 84.84(3), β = 83.08(2), and γ = 88.00(3)°, and V = 586(1) ų with Z = 2 for (MEDA)Cu2Br4 while (EEDA)Cu2Br4 has lattice constants a = 6.27(2), b = 7.78(2), and c = 13.12(3) Å, α = 84.69(4), β = 78.18(3), and γ = 88.17(7)°, and V = 623(3) ų with Z = 2. The dominant inorganic feature in both salts is anionic (CuBr2)nn− chains of edge-shared CuBr4 tetrahedra. The diammonium cations hydrogen bond these chains together into a unique double layer structure. For comparison purposes, the crystal structure of (CHA)PbBr3 (CHA+ = cyclohexylammonium)is reported (monoclinic, space group P21/n, a = 8.088(2) Å, b = 7.912(2) , Å, and c = 19.572(4) Å, β = 96.98(4)°, and V = 1243.2(4) ų with Z = 4). This contains (PbBr3)nn− halometalate chains, this time of face-shared PbBr6 octahedra. However, here the organic cations tie the chains together into the more common single layer structure. [ABSTRACT FROM AUTHOR]

Examines the coordination polymers of copper(I) halides. Correlation between copper(II) halides and dimethylquinoxaline; Relevance of pyrazine in nonchelating bidentate ligands; Determination of the structural analysis of the methyl groups.

Examines the reaction of 4,4'-dimethyl-2,2-bipyridine complexes with copper(I) and/or copper(II) bromide under a variety of conditions that led to the isolation of ten different crystalline materials. Copper-ligand bond distances; Thermal ellipsoids at 50% probability; Illustration of asymmetric unit of mixed valence species.

Presents a study which examined the magnetic properties of bimetallic compounds which contain linear M-Cu-M trimeric arrangements. Characteristics of trimetallic systems; Approach used in magnetic measurements of the compounds; Results of the study; Description of the exchange coupling for the cobalt (II) compound.