Debra K. Towle

The Crystal Structure and Magnetic Behavior of [Cu2(dien)2CI2](CIO4)2

Abstract The compound [Cu2(dien)2Cl2](C1O4)2 crystallizes in the orthorhombic system, space group Pbn21, with unit cell dimensions: a = 7.637(1) A, b = 13.549(3) A, and c = 20.866(4) A, with four molecules in the unit cell (Z = 4). The structure consists of dimeric [Cu2(dien)2C12]2+ units in which the coordination about copper(II) is highly distorted square-pyramidal. Magnetic susceptibility data shows a pair of exchanged coupled S = 1/2 ions and yields J = +0.4(3)cm−1 when the EPR g-factor value of = 2.104 is used.

Synthesis and characterization of the binuclear complex di-µ-oxo-bis[N,N′-bis(2-methylpyridyl)ethane-1,2-diamine]dimanganese(III,IV)perchlorate trihydrate,[(bispicen)MnO]2(ClO4)3·3H2O

The title complex, a new binuclear di-µ-oxo complex of manganese-(III) and -(IV) with a single tetradentate ligand in place of the previously reported bidentate bpy or phen ligands, has been synthesised and characterised by X-ray crystallography and cyclic voltammetry.

Synthesis and characterization of copper(II) iodo complexes of diethylenetriamine: isolation of an iodo-bridged copper(II) chain

Abstract The synthesis and characterization of two complexes of the formulation Cu(dien)I2, Cu(C4H13N3)I2, are described. The polymeric complex {[Cu(C4H13N3)I]I}n crystallizes in the orthorhombic space group Pnm21 with two molecules in a cell of dimensions a=8.873(2), b=8.890(3), c=6.658(1) A. The structure has been refined to a final R factor of 0.046 based on 596 independent observed intensities. The structure consists of chains of iodide-bridged copper(II) ions along the crystallographic c direction. The coordination geometry about copper is tetragonally-elongated (4+2) octahedral, the equatorial plane consisting of three nitrogen atoms from the dien ligand and one iodide while the axial sites are occupied by the other (chain-propagating) iodide ligands. The equatorial CuI bond length is 2.585(1) A while the axial distances are 3.325(1) and 3.371(1) A. The intrachain CuCu separation is 6.658(1) A, the c axis length, and the bridging CuI(2)Cu angle is 167.7(1)°. The magnetic susceptibility data for the polymeric complex reveal antiferromagnetic coupling. The monomeric complex [Cu(dien)I2] crystallizes in the monoclinic space group P21/a with four molecules in a cell of dimensions a=15.140(4), b=9.690(4), c=7.526(2) A, β=105.95(2)°. The structure has been refined to a final R factor of 0.0723 based on 2460 independent observed intensities. The complex is five coordinate, the structure being best described as a distorted trigonal bipyramid in which N(1) and N(3) are axial while N(2), I(1) and I(2) are in the trigonal plane. As is expected for a trigonal bipyramid, copper lies in the trigonal plane. The CuI distances are very different, one being 2.619(2) A while the other is 3.049(2) A.

Novel tetranuclear mixed-metal complexes containing the heteronuclear ions [MII{(OH)2CrA4}3]5+ and [MII{(OH)2CoA4}3]5+(A = amine ligand)

The synthesis and structural characterization of new tetranuclear complex ions with a central bivalent metal ion [MgII, ZnII, CoII, MnII, or NiII] octahedrally co-ordinated to six hydroxo groups which act as bridging ligands to three trivalent metal ions [CrIII or CoIII], is reported.