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CoII Cations (coii + cation)

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Chemistry100%

Selected Abstracts

A new three-dimensional cobalt(II) coordination polymer with a 4-connected CdSO4 -like topology

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009
Zhan-Lin Xu
The title cobalt(II) coordination polymer, poly[[diaquacobalt(II)]-,4 -3,3,-(p -phenylene)diacrylato], [Co(C12H8O4)(H2O)2]n, was obtained by reaction of Co(NO3)2·6H2O and 3,3,-(p -phenylene)diacrylic acid (H2L) under hydrothermal conditions. Each CoII cation sits on a centre of inversion and is hexacoordinated by six O-atom donors in an octahedral geometry. The CoII centres are connected by four centrosymmetric L2, anions, resulting in a three-dimensional framework structure. The coordinated water molecules and carboxylate O atoms form hydrogen-bond interactions, stabilizing the structure of the three-dimensional framework. Topologically, the framework represents a rare example of the three-dimensional 4-connected CdSO4 network type. The metal cations and the organic ligand both show in-plane coordination with respect to the extended structure. [source]

Two isomorphous cobalt(II) complexes: poly[[diaqua-,-2,5-dicarboxybenzene-1,4-dicarboxylato-,-1,2-di-4-pyridylethene-cobalt(II)] 1,2-di-4-pyridylethene solvate] and the 1,2-di-4-pyridylethane analogue

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2009
Ana Marķa Atria
The two isomorphous title structures, formulated as {[Co(C10H4O8)(C12H10N2)(H2O)2]·C12H10N2}n, (I), and {[Co(C10H4O8)(C12H12N2)(H2O)2]·C12H12N2}n, (II), respectively, are reported. They crystallize in the space group P with only one formula unit in the asymmetric unit, so that the organic ligands lie about inversion centres and the Co atom lies on an inversion centre. The Co atoms are octahedrally coordinated by a carboxylate O atom from 2,5-dicarboxybenzene-1,4-dicarboxylate (H2btc), one N atom from 1,2-di-4-pyridylethene (L) in (I) or from 1,2-di-4-pyridylethane (L) in (II), and one coordinated water molecule, plus their inversion-related species. This particular coordination results in a two-dimensional array, with an elemental unit in the shape of a parallelogram having the CoII cations at the corners, linked in one direction by L bridges and in the opposite direction by H2btc groups. The L solvent molecules act as pillars between parallel planes, linking them by strong hydrogen bonds where the H atoms lie midway between the formal donor/acceptor atoms in a `shared' mode. Comparison is made with structures presenting the same structural motif, strongly suggesting that the two-dimensional arrangement reported here might be a very stable robust building block for molecular engineering purposes. [source]

A novel cobalt(II) coordination polymer with an unusual four-connected 42.63.8 topology

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2008
Guo-Hua Wei
In the cobalt(II) coordination polymer poly[[(,2 -benzene-1,3-dicarboxylato){,2 -1,1,-[2,2,-oxybis(ethane-2,1-diyl)]di-1H -imidazole}cobalt(II)] monohydrate], {[Co(C10H14N4O)(C8H4O4)]·H2O}n, two crystallographically distinct CoII cations are four-coordinated by N2O2 donor sets in distorted tetrahedral geometries. The CoII centers are connected by benzene-1,3-dicarboxylate (m -BDC) anions, giving two types of linear chains, which are further joined via meso -helical 1,1,-[2,2,-oxybis(ethane-2,1-diyl)]di-1H -imidazole ligands to yield a thick two-dimensional slab. The compound displays a two-dimensional four-connected 42.63.8 topology, which is unprecedented in coordination polymers. [source]

Spontaneous Resolution of Chiral Polyoxometalate-Based Compounds Consisting of 3D Chiral Inorganic Skeletons Assembled from Different Helical Units

CHEMISTRY - A EUROPEAN JOURNAL, Issue 32 2008
Ya-Qian Lan Dr.
Abstract Four enantiomerically pure 3D chiral POM-based compounds, [Ni2(bbi)2(H2O)4V4O12],2,H2O (1,a and 1,b) and [Co(bbi)(H2O)V2O6] (2,a and 2,b) (bbi=1,1,-(1,4-butanediyl)bisimidazole) based on the achiral ligand, different vanadate chains, and different metal centers have been synthesized by hydrothermal methods. Single-crystal X-ray diffraction analyses revealed that 1,a and 1,b, and 2,a and 2,b, respectively, are enantiomers. In 1,a and 1,b two kinds of vanadate chains with different screw axes link Ni cations to generate 3D chiral inorganic skeletons, which are connected by the achiral bbi ligands to form complicated 3D 3,4-connected chiral self-penetrating frameworks with (72,8)(72,82,92)(73,82,10) topology. They represent the first examples of chiral self-penetrating frameworks known for polyoxometalate (POM) systems. Contrary to 1,a and 1,b, in 2,a and 2,b the vanadate chains link CoII cations to generate 3D chiral inorganic skeletons, which are assembled from two kinds of heterometallic helical units of opposite chirality along the c axes. The chiral inorganic skeletons are connected by bbi to form 3D 3,4-connected chiral POM-based frameworks with (62,8)2(62,82,102) topology. It is believed that the asymmetrical coordination modes of the metal cations in 1,a,2,b generate the initial chiral centers, and that the formation of the various helical units and the hydrogen bond interactions are responsible for preservation of the chirality and spontaneous resolution when the chirality is extended into the homochiral 3D-networks. This is the first known report of chiral POM-based compounds consisting of 3D chiral inorganic skeletons being obtained by spontaneous resolution upon crystallization in the absence of any chiral source, which may provide a rational strategy for synthesis of chiral POM-based compounds by using achiral ligands and POM helical units. [source]