Syntheses, Crystal Structures and Magnetic Properties of Ni(Ⅱ) and Mn(Ⅱ) Coordination Polymers Constructed from 5-(2'-Carboxylphenyl) Nicotate and 2,2'-Biimidazole

Two coordination polymers, namely {[Ni（cpna）（H2biim）（H2O）]·H2O}n （1） and {[Mn（cpna）（H2biim）]·H2O}n （2） （H2cpna = 5-（2＇-carboxylphenyl） nicotic acid, H2biim = 2,2＇- biimidazole）,have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, magnetic properties, and single-crystal X-ray diffraction. Compound 1 exhibits a one- dimensional （1D） step-like chain structure, which further builds a three-dimensional （3D） supramolecular architecture via O–HAAAO and N–HAAAO hydrogen-bonding and π-π stacking interactions. Compound 2 possesses a one-dimensional （1D） double chain structure, which is further assembled into a 3D supramolecular framework by N–HAAAO hydrogen bonding and π-π stacking interactions. Magnetic susceptibility measurement indicates that compound 1 shows a weak antiferromagnetic coupling between the nearest Ni（II） centers, with g = 2.11 and J = –1.87 cm^-1.

Syntheses,Crystal Structures and Luminescent Properties of Lead(Ⅱ) and Cadmium(Ⅱ) Coordination Polymers Constructed from Biphenyl-2,5,3′-tricarboxylate

Two coordination polymers, namely [Pb（Hbtc）（phen）]n（1） and {[Cd3（btc）2（H2O）4]·2H2O}n（2, H3btc = biphenyl-2,5,3＇-tricarboxylic acid, phen = 1,10-phenanthroline）, were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a zigzag chain 1D coordination network, which is further extended into a 3D supramolecular architecture via O–H···O hydrogen bonds and π-π packing interactions. Compound 2 features a 3D open framework based on a tricadmium（II） subunit, generating a trinodal 4,4,6-connected net with the 4,4,6T24 topology defined by the point symbol of（44·62）3（46·69）2. Thermal stability and luminescent properties of both compounds were studied and discussed.

Syntheses, Crystal Structures, and Magnetic Properties of the Cobalt(Ⅱ) and Nickel(Ⅱ) Coordination Polymers Constructed from 5-Halonicotinate and 2,2ˊ-Biimidazole

Two coordination polymers, namely [Co（5-Clnic）2（H2biim）]n 1 and {[Ni（5-Clnic）（Hbiim）]·H2O}n 2（5-Clnic H = 5-halonicotinic acid, H2 biim = 2,2ˊ-biimidazole）, were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a 1D chain coordination network, which is further extended into a 3D supramolecular architecture via N–H…O hydrogen bonds and π-π packing interactions. Compound 2 features a 1D chain structure based on the hexanuclear macrocycles. The adjacent 1D chains are held together into a 3D supramolecular framework via N–H…O and O–H…O hydrogen bonding interactions. Thermal stability and magnetic properties of both compounds were studied and discussed.

Syntheses, Crystal Structures and Magnetic Properties of Cobalt(Ⅱ) and Manganese(Ⅱ) Coordination Polymers Constructed from 5-(Pyridin-4-yl)Isophthalate Ligands

Two coordination polymers, namely {[Co（L）（H2O）]·H2O}n （1） and [Mn（L）（phen）]n （2, H2L = 5-（pyridin-4-yl）isophthalic acid, phen = 1,10-phenanthroline）, have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, magnetic properties, and single-crystal X-ray diffraction. 1 belongs to the triclinic system, space group Pī with α = 7.2188（7）, b = 10.0835（8）, c = 10.2069（7） ？, α = 113.713（7）, β = 99.490（7）, γ = 104.516（8）o, V = 628.24（9） ？3, C13H11NCoO6, Mr = 336.16, Z = 2, Dc = 1.777 Mg/m3, μ（MoKα） = 1.395 mm–1, F（000） = 342, S = 1.041, the final R = 0.0381 and wR = 0.0819 for 3744 observed reflections （I 〉 2σ（I）） and R = 0.0448 and wR = 0.0874 for all data. 2 belongs to the monoclinic system, space group P2/c with α = 12.9185（3）, b = 10.4343（2）, c = 31.7650（6） ？, β = 101.282（2）o, V = 4199.08（13） ？3, C50H30N6Mn2O8, Mr = 952.68, Z = 4, Dc = 1.507 Mg/m3, μ（MoKα） = 5.447 mm–1, F（000） = 1944, S = 1.128, the final R = 0.1003 and wR = 0.1052 for 8247 observed reflections （I 〉 2σ（I）） and R = 0.2595 and wR = 0.2625 for all data. Single-crystal X-ray diffraction studies show that compound 1 features a 2D sheet structure based on a dicobalt（II） subunit, which is further extended into a 3D metal-organic supramolecular framework by O–H… hydrogen bond. Compound 2 also possesses a 2D sheet, which is held together into a 3D supramolecular architecture via C–H… hydrogen bond and π-π stacking interactions. Magnetic studies for compound 2 show antiferromagnetic coupling between the adjacent metal centers, with J = –11.8 cm–1 and g = 2.12 for 2.

Investigation the Porous Collagen-Chitosan/Glycosaminoglycans for Corneal Cell Culture as Tissue Engineering Scaffold

The objective of this study was to produce the porous col lagen-chitosan/Gl ycosanminglycans(GAG) for corneal cell-seed implant as a t hree-dimensional tissue engineering scaffold to improve the regeneration cornea s.The effect of various content of glycerol as form porous agent to collagen-ch i tosan/GAG preserved a porous dimensional structure was investigated.The heat-dr ying was used to prepare porous collagen-chitosan /GAG scaffold.The pore morpho logy of collagen-chitosan/GAG was controlled by changing the concentration of g lycerol solution and drying methods.The porous structure morphology was observed by SEM.The diameter of the pores form 10 to 50 μm.The highly porous scaffold had interconnecting pores.The corneal cell morphology was observed under the li ght microscope.These results suggest that collagen-chitosan/GAG showed that cor neal cell have formed confluent layers and resemble the surface of normal cornea l cell surface.

Electronic Structure and Properties of Cu Metal~*

The main purpose of the present work is to introduce a simple and effective method in order to analyse the structure and properties of both pure metals and alloys. The main points of this method are to use one-atom state instead of one-electron state and a potential function with many-atom interactions instead of Schrodinger equation. The atomic state of pure metals can be constructed by some basic atomic states which obey the Pauli exclusion principle. The electronic structure of Cu metal which is [Ar](3d_n)^(4.89)(3d_c)^(4.77)(4s_f)^(1.34) has been determined by self-conslstency method. Theoretical values of many properties of Cu metal, such as lattice constant, cohesive energy, bulk modulus and temperature dependence of thermal expansion coefficient calculated according to this electronic structure are in good agreement with experiments.

Synthesis,crystal structure and thermal behavior of Rb(NTO)·H_2O

The Rb(NTO) .H2O crystal has been synthesized by reaction of 3-nitro-l,2,4-triazole-5-one (NTO) with Rb2CO3 in aqueous solution. Its crystal structure has been determined. The crystal belongs to monoclinic system. Crystal structure data: space group P21/ n; a = 0.633 0(1), b = 0.824 1(2), c =1.296 4(3) nm; β = 97.90(1)°; V = 0.669 9 (2) nm3, Z = 4, Dc= 2.306 g/cm3,μ = 7.365 nm-1, F(000) = 448. An eight coordinated compound is formed between Rb+ with oxygen atoms and nitrogen atoms. A layer structure is formed by coordination bonds and hydrogen bonds. The thermal decomposition mechanism of this coordination compound is discussed.