Synthesis and Structure of a Mononuclear Co(II) Complex Based on a Salicylideneaniline Ligand, (Z)-4-(2- Hydroxybenzylideneamino)-2-hydroxybenzoic Acid

The reaction of a new salicylideneaniline ligand, (Z)-4-(2-hydroxybenzylidenea- mino)-2-hydroxybenzoic acid (HL) with CoCl2·6H2O yields one Co(II) complex, [CoL2(CH3OH)2 (H2O)2]. This complex crystallizes in monoclinic P21/n space group, with a = 5.4992(5), b = 18.2200(15), c = 14.8678(14) , β = 98.64(1)°, V = 1472.8(2) 3, C30H32CoN2O12, Mr = 671.51, Z = 2, Dc = 1.51416 g/cm3, F(000) = 698, μ = 0.652 mm–1, T = 298(2) K, R = 0.0514 and wR = 0.1735 for all 2675 observed reflections (I > 2σ(I)). In this complex, the imine N does not link to Co(II) and a remarkable torsion around C=N bond is observed. Through hydrogen bonds, the monomers aggregate into an interesting "Z-shape" framework.     

Synthesis and Crystal Structure of a Mixed-ligand Manganese（Ⅱ） Complex Containing Abundant Hydrogen-bonding Interactions

A new mixed-ligand Mn(II)complex,namely [Mn(bipy)2(Huca)]·5H2O(1,bipy = 2,2'-bipyridine,and H3uca = uracil-5-carboxylic acid)has been prepared and characterized by single-crystal X-ray diffraction,FT-IR spectroscopy and thermogravimetric analysis.It crystallizes in monoclinic,space group C2/c with a = 23.597(8),b = 16.434(5),c = 15.531(6),β = 112.785(6)o,C25H28MnN6O9,Mr = 611.47,V = 5553(3)3,Z = 8,μ = 0.538,Dc = 1.463 g/cm3,F(000)= 2536,R = 0.0441 and wR = 0.1230 for all 5227 observed reflections(I > 2σ(I)).The manganese(II)center is surrounded by three bidentate chelating ligands,and it displays a severely distorted octahedral geometry,with cis angles ranging from 72.14(6)to 109.78(6)o.Extensive intermolecular hydrogen bonds link the [Mn(bipy)2(Huca)] monomers and lattice water molecules to yield a three-dimensional supramolecular framework.TGA shows complete removal of all lattice water molecules above 270 ℃.     

Synthesis and Characterization of Two Mononuclear Mn~Ⅲ Compounds with Mixed Schiff Base Ligands

Two mononuclear Mn compounds of Mn III (salen)(L 1) and Mn III (salen)(L 2) (H 2 salen=N,N-ethylenebis-(salicylideneaminato),L 1=4-(2-hydroxybenzylideneamino)benzoic acid and L 2=4-(2-hydroxybenzylideneamino)-2-hydroxybenzoic acid) have been prepared and characterized by X-ray crystallography.Both compounds crystallize in the monoclinic system,space group P2 1 /c with a=14.351(4),b=14.955(3),c=11.869(3) and β=91.529(3)° for 1;and those for 2:a=14.439(9),b=15.217(9),c=11.660(7) and β=91.648(1)°.The compounds have similar structures,in which the Mn III center adopts a distorted square-pyramidal geometry with the basal plane constructed by two N and two O atoms from the salen ligand and the apical position occupied by the carboxylate O atom from L 1 or L 2 ligand.The voltammetric behavior of the compounds is examined,which shows quasi-reversible one-electron reduction of Mn(Ⅲ) to Mn(Ⅱ).The reduction potentials of both compounds fall between-0.33 V [E 0 (O 2 /O 2 ·)] and 0.65 V [E 0 (1 O 2 /O 2 ·)],which suggest that 1 and 2 could be potential mimics of Mn-SOD.     

Synthesis and Crystal Structure of a 2D Cu Framework Constructed from Dinuclear Building Units

A novel 2D Cu coordination polymer [Cu4(pca)4(H2O)2(DMSO)2·2DMSO·2H2O]n(2, H2 pca = pyrazole-3-carboxylic acid) has been prepared by dissolving a dinuclear Cu complex Cu2(py)3(pca)2(H2O)·(H2O)(1) in DMSO solution and structurally characterized by X-ray diffraction. The polymer crystallizes in space group P1 with a = 9.538(3), b = 9.714(3), c = 10.765(3) A, α = 86.492(6), β = 84.007(7), γ = 82.592(6)o, Mr = 1079.04, V = 982.4(5) A3, Z = 1, Dc = 1.824 g/cm3, μ = 2.425 mm-1 and F(000) = 548. The final refinement gave R = 0.0785 and w R = 0.1940 for 2787 reflections with I 2σ(I). The structure of 2 consists of Cu4(pca)4(H2O)2(DMSO)2·2DMSO·2H2O units, which can be viewed as two dinuclear subunits of Cu2(pca)2(H2O)2 and Cu2(pca)2(DMSO)2 connected to each other alternately, with solvent DMSO and H2 O molecules around. The framework features a grid-like topology, with the walls of the grids composed of Cu4(pca)4 units, and the coordinated solvent molecules trapped in the grids.     

A Pyridine-copper Inclusion Complex of a New Tripodal Ligand

1 INTRODUCTION Numerous recent reports have been focused on the construction of supramolecular architectures by using some special tripodal ligands with aromatic ring platforms[1～5]. Mixing this kind of ligands with metal ions in a suitable solution generally yields typical 1D, 2D and 3D coordination polymers or large nanometer-sized cavities supposed to be use- ful for catalysis, molecular selection, ion exchange, specific chemical transformations et al.[6～11]. Now our group is inte…     

Synthesis and Crystal Structure of a Salicylaldehyde Ethylene Diamine Schiff Base Manganese (Ⅲ) Complex

1 INTRODUCTION Manganese is one of several first-row transition metal elements that have been found to play an important role in most biological systems. Perhaps the best known is in the process of photosynthesis during which water is oxidized to yield dioxygen, and it is generally believed that the process is related to a tetranuclear manganese cluster[1]. Other aspects of biological chemistry of manganese, such as three mononuclear manganese enzymes: manganese superoxide dismutase, per…