Duan-Jun Xu

Synthesis and Crystal Structure of a Cadmium(II) Complex with 2,2′-diamino-4,4′-bis-1,3-thiazole

Crystals of the title complex with diaminobithiazole (DABT) were obtained by a solution diffusion method. X-ray diffraction analysis shows the complex to be monoclinic, space group P21/c with cell dimensions a=11.684(2), b=13.625(2), c=14.859(1) Å and β=109.970(7)°; R=0.026. The Cd(II) atom lies in a distorted octahedral environment with two DABT and two Cl ligands in a cis arrangement. The average internal dihedral angle of 9.3° between thiazole rings of DABT shows the twisted structure of the ligand in the complex. The Cd(II) atom deviates by some -0.570 Å from the mean plane of the thiazole ring containing N(4), but the Cd-N(4) bond is the shortest among four Cd-N bonds in the structure. Intramolecular H-bonds between Cl atoms and amino groups stabilize the cis-configuration of the complex.

Synthesis and Crystal structure of an Iminodiacetatocobalt(Ii) complex with Benzimidazole

The title complex, (C7H6N2)3(C4H5NO4)Co·2H2O, has been prepared and its crystal structure determined by single-crystal X-ray diffraction methods. The cobalt atom is octahedrally coordinated by three benzimidazole molecules and an iminodiacetate anion. The anion coordinates facially as a tridentate. Extensive intermolecular hydrogen bonding and C−H· · ·π interactions occur in the crystal. Thermal decomposition of the complex has been studied by thermogravimetry and differential scanning calorimetry. The IR spectral assignments were based on the molecular structure.

THE POLYMERIC COPPER(II) COMPLEX, 2,2′-BIPYRIDINE-N,N′-(μ-NICOTINATO-O, O′:N) MONOAQUACOPPER (II) NITRATE DIHYDRATE

Abstract The nicotinate complex of Cu(II), 2,2′-bipyridine(nicotinato)monoaquacopper(II) nitrate dihydrate has been prepared and its crystal structure has been determined by means of X-ray methods. The nicotinate anions bridge adjacent Cu(II) atoms through both the pyridine N atom and the carboxyl group to form infinite chains. The carboxyl group of the nicotinate anion coordinates to the Cu(II) atom as a chelate. Based on the molecular structure the infrared spectrum is discussed.

SYNTHESIS AND STRUCTURE OF A POLYMERIC 1,3-BENZENEDICARBOXYLATO COMPLEX OF Mn(II) WITH PHENANTHROLINE

Abstract A novel Mn(II) complex bridged by 1,3-benzenedicarboxylate (BDC) has been synthesized by the diffusion method. The complex crystallizes in space group P21/c with a = 8.345(2), b = 10.427(1), c = 18.756(2) Å, β = 100.19(1)°. Each BDC bridges three Mn(II) atoms through two carboxyl groups with different coordination modes to form a complex polymeric chain. The coordination geometry around the Mn(II) atom is seriously distorted from the normal octahedron. Large deviations of the donor atoms out of the coordination planes and unexpected bond angles around Mn(II) and donor O atoms suggest the existence of an electrostatic interaction between Mn(II) and donor atoms in the complex. Close stacking of aromatic rings is observed in the complex, the distance between the neighboring phen planes being 3.2085 Å.

Synthesis and catalytic properties of a Ni(II) complex with tetraglycol aldehyde bis(methionine) Schiff base

Abstract A new Ni(II) complex with an amino acid Schiff base has been prepared by reaction of the Li(I) salt of the tetraglycol aldehyde bis(methionine) Schiff base and Ni(NO 3 )·6H 2 O in methanol solution. Characterization by elemental analysis, magnetic susceptibility and infrared spectroscopy suggests a binuclear structure. The Ni(II) complex shows catalytic polymerization activity.

Separation of rosin acids by molecular recognition: crystal structure of the complex of neoabietic acid with 2-amino-6-methyl-pyridine

Neoabietic acid has been separated from gum rosin mixture by the aid of molecular recognition using 2-amino-6-methyl-pyridine as recognition reagent. The complex of neoabietic acid with 2-amino-6-methy-pyridine crystallizes from ether solution in the monoclinic, space group P21 with cell parameters of a = 7.370(1), b = 8.692(1), c = 18.365(2) Å, β = 92.53(1)°,V = 1175.3(2) Å3 and Z = 2. X-ray structure analysis shows that an extensive H-bonding network exists between neoabietic acid and amino(methyl)pyridine, which is considered as one of the factors resulting in successfully separating the neoabietic acid from the gum rosin mixture.

Poly[[tris­(μ3-2-oxidopyridinium-3-carboxyl­ato)manganese(II)sodium(I)] monohydrate]

In the crystal structure of the title compound, {[MnNa(C6H4NO3)3]·H2O}n, the MnII cation is located on a threefold rotation axis and is chelated by three 2-oxidopyridinium-3-carboxylate (opc) anions in an octahedal coordination. The NaI cation is located on a threefold rotation axis and is surrounded by six O atoms from three opc anions. The opc anions link the Mn and Na cations, forming a three-dimensional polymeric structure. The uncoordinated water molecule, located on a threefold rotation axis, is equally disordered over two sites. The three-dimensional network is consolidated by N—H⋯O hydrogen bonds.

Synthesis and crystal structure of aqua (2,2′-diamino-4,4′-bi-1,3-thiazole) (oxydiacetato)manganese(II) trihydrate

The title compound crystallizes in the triclinic space group with a = 7.194(3), b = 9.790(5), c = 12.492(1) Å, α = 82.407(16), β = 86.664(15), γ = 89.882(15)°. The Mn(II) complex assumes distorted octahedral coordination geometry, formed by diaminobithiazole (DABT), an oxydiacetate dianion (ODA) and a water molecule. The tridentate ODA ion chelates to the Mn(II) atom in a meridional configuration. Each carboxyl group coordinates to the Mn(II) atom as a monodentate. Uncoordinated carboxyl oxygen atoms are involved in a hydrogen-bonding network. DABT chelates to the Mn(II) atom with a coplanar configuration. Coordinated water is hydrogen bonded to carboxyl groups of ODA of a neighboring complex to form supramolecular chains. A π–π stacking interaction involving thiazole rings occurs between adjacent supramolecular chains. A difference of 180 cm−1 between asymmetric and symmetric stretching vibrations of the carboxyl group corresponds to the extensive hydrogen-bonding network involving the carboxyl group.

Synthesis and Crystal Structure of a Polymeric Benzimidazole Complex of Mn(II) Bridged by Succinate

The title complex has been prepared and its crystal structure determined by X-ray diffraction methods. The Mn (II) complex is seven coordinate with two benzimidazole (bimid)ligands in axial positions and two succinate and one bimid ligands in the equatorial plane. The succinate bridges Mn (II) atoms to form polymeric chains, linked by intermolecular H-bonding. Free bimid molecules occur in the crystal structure; they link Mn (II) complexes with H-bonds involving N atoms. Aromatic stacking between bimid rings is observed, resulting in a gauche confirmation of succinate in the structure. The IR spectrum is assigned based on the crystal structure. The difference of 139cm-1 between symmetric and asymmetric stretching vibrations of carboxyl groups is in line with seven coordination at the Mn (II) atom.

Synthesis and crystal structure of diiodobis(thiourea)mercury (ii)-bis(diazafluoren-9-one)

The title compound, [HgI2(CH4N2S)2]·2C11H6N2O, is comprised of the Hg(II)–thiourea complex and free 4,5-diazafluoren-9-one (DAFONE). The complex assumes a distorted tetrahedral geometry at mercury formed by two thiourea molecules and two I− ions, the S–Hg–S angle [103.7°] being significantly smaller than S–Hg–I angles (115.2 and 114.3°). The complex and DAFONE molecules link to each other via hydrogen bonding to form a supramolecular structure. Significant π–π stacking is observed between neighboring DAFONE molecules.