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Research describes the synthesis of three cobalt(II)-pyromellitate complexes, purple, red, and pink, which exhibit hydrogen-bonded and coordination-bonded structures. The magnetic properties of purple complex consists of three ground states and two types of hysteresis loops. Data indicate that the red and pink complexes are paramagnets.

Research has been conducted on the inorganic or/and organic molecule assemblies. The use of polyoxovanadate as a structural building block in the hydrogen bonded inorganic-organic three-dimensional structure synthesis is described.

The crystal structure of copper(II) intercalation compounds, ((Cu(CA)(H2O)2)(G))n, (H2CA = chloranilic acid, G = 2,5-dimethylpyrazine (1) and phenazine(2)) consists of one dimensional (Cu(CA)(H2O)2)m chains. The chains intercalate G1 molecules to form a stack while G2 molecules are linked to (Cu(CA)(H2O))n chain. The Cu-atom exhibits a six coordinate geometry having two bis-chelating CA2-ions and water molecules. This provides a linear coplanar chain structure. X-ray crystallography and magnetic susceptibility help to understand the structure of the complex .

The synthesis and characterization of three coordinated networks having the dimeric [Cu.sub.2][(C[O.sub.2]).sub.4] node connected by different geometrical isomers of cyclohexane carboxylates is presented. The results have shown that the magnetic properties of all the three compounds are dominated by the strong Cu-Cu antiferromagnetic interaction resulting in singlet-triplet gaps.

The hydrothermal reaction of nickel(II) and mixtures of geometric isomers of 1,4-Cy-clohexanedicarboxylate results in total segregation in the solids based on a common Ni3(OH)2 linear chain secondary building unit connected by the fully deprotonated acid to form 3D frameworks with channels containing water molecules. Both are magnetic at low temperatures and one displays a reversible transformation from a ferrimagnet to ferromagnet upon partial hydration and rehydration.

Two weakly coupled paramagnetic polymorphs of M(super II)-(trans-3)(3-pyridyl)acrylate)(H2O)(sub 2) were selectively prepared hydrothermally at 120 and 170 degree Celsius. The structures consisted of wither an unusual network showing threadings of three sublattices and knots in one case and a Zwitterionic chain for the other, respectively.

The findings of a synthesis and characterization of two new copper II compounds are presented. The contents, structure and formation of these crystals are also explained.

Research has been conducted on porous magnetic material that orders ferrimagnetically at 60.5 K. The authors describe the results of synthesis and characterization of this material.

Single crystals of three coordination networks containing the Cu2(COO)4 core bridged by cyclohexane have been hydrothermally prepared by the reaction of 1,4-cyclohexanedicarboxylic (1,4-H2chdc) or 1,3,5-cyclohexanetricarboxylic (1,3,5-H3chtc) acid and Cu(NO3)2·6H2O. We report their characterizations by single-crystal X-ray structure determinations, IR spectroscopy, thermal analyses, and their magnetic properties. [Cu2(trans-1,4-chdc)2] (1) consists of 4 × 4 grids with the dimeric nodes connected by the trans-1,4-chdc, and these grids are then connected to each other by Cu-O bonds, resulting in a porous network (void volume of 130 ų per cell or 25%) with no solvent in its cavities. [Cu2(cis-1,4-chdc)2(H2O)2] (2) consists of two-legged ladders where the dimer nodes are bridged by pairs of cis-1,4-chdc and the water molecules cap the ends of the Cu dimers. [Cu2(1,3,5-Hchtc)2] (3) displays 4 × 4 grids, but each dimeric node is connected to its neighbors within the same grid by Cu-O bonds to form a layered network which further makes hydrogen-bond interactions with its neighbors. 2 and 3 have compact structures without any space for solvents. IR and DT-TGA confirm the absence of water in the empty channels of 1, while IR shows the presence of both protonated and deprotonated carboxyl groups for 3. The magnetic properties of all three compounds are dominated by the strong Cu-Cu antiferromagnetic interaction resulting in singlet-triplet gaps of 450-500 K. [ABSTRACT FROM AUTHOR]

Describes the synthesis, characterization and reversible guest-exchange chemistry of a porous Cobalt(II)-hydroxide layer structure pillared with trans-1,4-cyclohexanedicarboxylate magnetic material that orders ferrimagnetically. In-situ single crystal and powder X-ray diffraction analyses; Decrease in interlayer spacing; Loss of two water molecules per formula unit; Single crystal structure of the fully dehydrated material.

We present the hydrothermal synthesis, characterization (IR, DT-TGA), single-crystal structures, and magnetic properties of two polymorphs of trans-3(3-pyridyl)acrylate of cobalt(II) and of nickel(II), MII(C8H6NO2)2(H2O)2. Hydrothermal reaction at 120 or 170 °C results exclusively in the different polymorphs. The infrared spectra and thermogravimetric analyses of the complexes are almost similar for the two polymorphs but show a difference between cobalt and nickel in energies of the vibrational modes and in the decomposition temperatures. The crystal structures of the two polymorphs are quite different; one crystallizes in a monoclinic space group and the other in a triclinic. This major difference is due to the different stereochemistry, cis or trans, of the coordination at the metal sites. When it is trans-MN2O4, it results in the monoclinic cell consisting of a 3D-network of metals bridged by the ligands through single bonds (M-N and M-O). There is threading of three sublattices up to 2a × 4b × 2c, at which point the three sublattices are knotted into one infinite framework. When it is cis-MN2O4, it results in the triclinic cell and consists of Zwitterionic linear chains of metals bridged by one single ligand via the pyridine and a bidentate carboxylate group and the other ligand is bonded only via the pyridine while its carboxylate end is free. All four compounds are paramagnetic with Weiss constants suggesting weak interactions. [ABSTRACT FROM AUTHOR]

We present the hydrothermal synthesis, characterization (IR, DT-TGA), single-crystal structures, and magnetic properties of two polymorphs of trans-3(3-pyridyl)acrylate of cobalt(II) and of nickel(II), M(II)(C(8)H(6)NO(2))(2)(H(2)O)(2). Hydrothermal reaction at 120 or 170 degrees C results exclusively in the different polymorphs. The infrared spectra and thermogravimetric analyses of the complexes are almost similar for the two polymorphs but show a difference between cobalt and nickel in energies of the vibrational modes and in the decomposition temperatures. The crystal structures of the two polymorphs are quite different; one crystallizes in a monoclinic space group and the other in a triclinic. This major difference is due to the different stereochemistry, cis or trans, of the coordination at the metal sites. When it is trans-MN(2)O(4), it results in the monoclinic cell consisting of a 3D-network of metals bridged by the ligands through single bonds (M-N and M-O). There is threading of three sublattices up to 2a x 4b x 2c, at which point the three sublattices are knotted into one infinite framework. When it is cis-MN(2)O(4), it results in the triclinic cell and consists of Zwitterionic linear chains of metals bridged by one single ligand via the pyridine and a bidentate carboxylate group and the other ligand is bonded only via the pyridine while its carboxylate end is free. All four compounds are paramagnetic with Weiss constants suggesting weak interactions.

Two new copper(II) compounds of chloranilate and 2,2':6',2' '-terpyridine have been synthesized, and the structures have been solved by the single-crystal X-ray diffraction method. The crystal structure of [[Cu(2)(CA)(terpy)(2)][Cu(CA)(2)]](n)(1), where H(2)CA = chloranilic acid and terpy = 2,2':6',2' '-terpyridine, consists of two modules, the dimer unit [Cu(2)(CA)(terpy)(2)](2+) and the anionic mononuclear unit [Cu(CA)(2)](2)(-), forming an alternated chain. The chain is stabilized by semicoordinating and additional but efficient secondary bonding interactions. The crystal structure of [[Cu(2)(CA)(terpy)(2)(dmso)(2)][Cu(CA)(2)(dmso)(2)](EtOH)](n)(2), where dmso = dimethyl sulfoxide, consists of solvent molecules and two discrete modules, the dimer unit [Cu(2)(CA)(terpy)(2)(dmso)(2)](2+) and the anionic mononuclear unit [Cu(CA)(2)(dmso)(2)](2)(-). The dimer units form a layer by secondary bonding interactions, and the monomer units and ethanol molecules are introduced between the layers. The magnetic properties of 1 and 2 have been investigated in the temperature range 2.0-300 K. A weak ferromagnetic interaction was observed in 1, J(a) = 2.36 cm(-)(1) and zJ(b) = -0.68 cm(-)(1) while no exchange coupling was observed in 2.