Pingping Sun

Crystal Structure and Characterization of the Dinuclear Cd(II) Complex [Cd(H2O)2(ο-HOC6H4COO)2]2

The structure of a new binuclear cadmium (II) complex, [Cd(H2O)2(Sal)2]2 (Sal= salicylate), has been determined by X-ray crystallography. It was also characterized by elemental analysis, its IR spectrum and thermogravimetric-differential scanning calorimetry (TG-DSC). It crystallizes in the monoclinic system, space group P2(1)/c, with lattice parameters a = 15.742(3) A, b = 12.451(3) A, c = 7.7225(15) A, beta = 96.07(3)degrees and Z = 4. Two cadmium (II) ions are bridged by two mu(2)-carboxy oxygen atoms. Each cadmium atom lies in a distorted capped octahedron coordination geometry. The thermal gravimetry (TG) data indicate that there are four discrete decomposition steps with two endothermic peaks and one exothermic peak. The final thermal decomposition product is CdO.

Synthesis, crystal structure and thermal stability of bis(1,10-phenanthroline) cobalt(II) cyanide ethanol solvate dihydrate

The compound [Co(phen)2(CN)2]·EtOH·2H2O was obtained by reaction of Co(CN)2 and 1,10-phenanthroline (phen) in 95% EtOH solution and characterized using IR and UV spectroscopy, thermogravimetric-differential thermal analysis (TG-DTA) and X-ray crystallography. The deep-brown crystal is triclinic, space group P , with lattice parameters a = 10.356(2), b = 10.505(2), c = 12.148(2) Å, α = 79.19(3), β = 79.68(3), γ = 86.71(3)° and Z = 2. The compound contains a six-coordinate cobalt atom chelated by two phen ligands and two cyanide anions in a cis arrangement. One ethanol solvate molecule and two water molecules complete the crystal structure. In the solid state, the title compound forms a network structure through hydrogen bonds. Intermolecular hydrogen bonds connect the [Co(phen)2(CN)2], ethanol and H2O moieties. TG data indicate that thermal decomposition of the compound takes place in four steps, and the final product of thermal decomposition is CoC2. Elemental analysis, IR and UV spectra are in agreement with the structural data.

Synthesis, structures and thermal properties of three crystalline polymorphs of the bis(n-phenylmethylbenzimidazole-n) dichloro cobalt(II) complex CoCl2(C7H5N2CH2Ph)2

Three polymorphic, crystalline specimens of the bis(N-phenylmethylbenzimidazole-N)dichloro cobalt(II) complex CoCl2(C7H5N2CH2Ph)2 have been obtained from different solvents and their structures determined by X-ray diffraction. X-ray analysis revealed that the three compounds have the same composition; however, details of their molecular structure differ significantly. The α-form is triclinic, space group , with lattice parameters a = 10.396(2), b = 10.439(2), c = 13.665(3) Å, α = 90.13(3), β = 110.15(3), γ = 110.46(3)°; both the β- and γ-forms crystallize in the monoclinic space group P21/c, with lattice parameters a = 12.884(3), b = 9.612(2), c = 21.761(7) Å, β = 108.02(3)° for the β-form and a = 7.357(2), b = 18.337(4), c = 19.572(5) Å, β = 107.46(3)° for the γ-form. In all three cases, the asymmetric unit consists of [CoCl2(C7H5N2CH2Ph)2] molecules. The geometry of their CoCl2N2 chromophore is a distorted tetrahedron. Thermogravimetric analysis (TGA) indicates that they have different thermal stabilities and give rise to different resting residues. The electronic and IR spectra were also investigated. Analysis of the extent to which the stereochemistry of the constituent molecules in polymorphs A, B and C differ was examined using the program MATCHIT. There are major differences in the atomic positions of chemically related atoms that are not related to space group differences. The differences are caused by significant torsional motions of the flexible groups that seem to be caused by changes in the solvent media from which the crystals were obtained. Thus, the solvent cage of the parent solutions seems to be, at least partially, responsible for the incidence of crystalline polymorphism.

Structure of tetra(β-propiophenone-1,2,4,triazole-N4) dichloro metal hexahydrate complex: [MCl2(C2H2N3CH2CH2COPh)4]⋅6H2O (M = Ni, Co)

The crystal and molecular structures of the complexes of [NiCl2(N4-trzCH2CH2 COPh)4]⋅6H2O and [CoCl2(N4-trzCH2CH2COPh)4]⋅ 6H2O (trz = 1,2,4-triazole) have been determined by X-ray crystallography. They are isomorphous. The crystal structures are very similar. They both crystallize in the monoclinic system, space group P21/c, Z = 4; the former with lattice parameters a = 8.0391(2), b = 10.8215(2), c = 29.0133(2) Å, β = 94.792(1)°; the latter with a = 8.039(2), b = 10.822(2), c = 29.013(6) Å, β = 94.79(3)°. They all display almost perfect octahedral coordination geometry around the central metal atom. Each metal atom is coordinated by four N atoms of triazole from four β-propiophenone-1,2,4-triazole ligands and two chloride anions in a trans arrangement. In addition to the coordinating metal complex, there are six uncoordinated water molecules, which complete the crystal structure. In the solid state, the title two compounds form three dimensional network structures through hydrogen bonds. The intermolecular hydrogen bonds connect the [MCl2(C2H2N3CH2CH2COPh)4] and H2O moieties.

Synthesis and Structural Studies of Novel 1-[(4-Substituted-2-{4-[(Substituted Benzyl)Oxyl)Phenyl}-1,3-Dioxolan-2-Yl)Methyl]-1H-1,2,4-Triazole

Ten new triazole compounds containing 1,3-dioxolane were designed and synthesized. Single crystals of the compound (7) were obtained by recrystallization from acetic ether at room temperature. Their structures were identified by means of EA, IR, 1H NMR spectra, and X-ray crystallography. Preliminary bioassays showed that the synthesized compounds exhibited some activities of fungicide and plant growth regulators.

A dinuclear CoII complex: bis(μ-di­hydrogen phosphato-κ2O:O′)­bis­[(bipyridine-κ2N,N′)(di­hydrogen phosphato-κO)­cobalt(II)]

The title compound, [Co 2 (H H PO 4 ) 4 (C 10 H 8 N 2 ) 2 ], is dinuclear, centred on a symmetry centre of the P1 space group. Each Co atom has a distorted square-pyramidal coordination involving two N atoms from a bipyridine molecule and three O atoms from two bridging and one terminal dihydrogen orthophosphate anion. The molecular structure and packing are stabilized by intermolecular hydrogen-bond interactions.

Bis(1-aceto­phenone-1H-benzotriazole-κN3)­di­chloro­zinc(II)

In the title compound, [ZnCl2(C6H4N3CH2COPh)2], the zinc ion is coordinated by two Cl− anions and two N atoms of two triazole ligands, forming a distorted tetrahedral geometry. The molecular structure and packing are stabilized by van der Waals interactions.