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From: | Frederik Boyer |
Subject: | [Beaver-devel] stratify |
Date: | Sat, 30 Sep 2006 16:14:56 +0200 |
User-agent: | Thunderbird 1.5.0.7 (Windows/20060909) |
O hydrogen-bonding interactions between water molecules, carboxyl hydroxy groups and carboxylate groups. Each conformer resides on a centre of inversion. O interactions stabilize the crystal structure. The anions do not coordinate to the nickel, but act as counter-ions. The Co atom and the mid-point of the bipyridine group are located on inversion centres. The transition metal cation is six-coordinated by three ethylenediamine molecules in an octahedral geometry. The ribbons are held together by a network of hydrogen bonds. In the crystal structure, two of the molecules form a hydrogen-bonded dimer, while the third forms a centrosymmetric hydrogen-bonded dimer with its symmetry-equivalent molecule. O hydrogen bonds, forming chains along the c axis. This is the first crystal structure of a metal complex of sulfamerazine. The geometry of the complex is comparable to that in a previously reported nitrate salt. The deviation from a planar arrangement can be attributed to non-classical hydrogen bonds and steric factors. The Cu atom shows a square-pyramidal coordination geometry. The ZnII atom, located on an inversion centre, is coordinated by two N atoms and two O atoms from two Schiff base ligands in a square-planar geometry. The ribbons are held together by a network of hydrogen bonds. O hydrogen bonds link the molecules into dimers, which may be effective in the stabilization of the crystal structure. N hydrogen-bonding interactions results in the formation of a dimer. The anions do not coordinate to the nickel, but act as counter-ions. In the crystal structure, two of the molecules form a hydrogen-bonded dimer, while the third forms a centrosymmetric hydrogen-bonded dimer with its symmetry-equivalent molecule. O hydrogen bonds help to stabilize the structure. O hydrogen bonding involving the water molecules located on a twofold axis links the complex molecules into a three-dimensional network. The cation and all atoms of the anion lie on a mirror plane. This leads to the formation of alternate hydrophilic and hydrophobic layers. Hydrogen bonding between solvent water molecules and complex cations stabilizes the crystal structure. |
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