Two 2D uranyl coordination complexes showing effective photocatalytic degradation of Rhodamine B and mechanism study

Two new hydrostable two-dimensional(2 D) uranyl coordination complexes [(UO_2)_5(μ_3-O)_2(nbca)_2].7 H_2O(1) and [(UO_2)_3(nbca)_2(H_2O)_3]·2 H_2O(2)(H_3 nbca=5-nitro-1,2,3-benzenetricarboxylic acid) were hydrothermal synthesized.Single-crystal structural refinements reveal that both of the two complexes were formed by the packing of 2D uranyl coordination sheets via the hydrogen bonds.The nbca ligand coordinating to the uranyl polyhedron centers constructed the 2D sheets.There are UO_8 hexagonal bipyramids and UO_7 pentagonal bipyramids in 1 while only U07 pentagonal bipyramids in 2.Photocatalytic degradation of rhodamine B(RhB) in aqueous solution was studied.Complex 2 possesses better performance than 1 with 96.2 % of the RhB was degraded in only 60 min.Mechanism studies reveal that the dissolved oxygens are essential to the RhB degradation.The photocurrent density of 2 is more stable than that of 1,which indicating the stronger ability to separate photoexcited electrons and hole pairs of 2.     

基于2，5-双(三氟甲基)对苯二甲酸配体的锌配合物的合成、晶体结构及性质

利用2,5-双（三氟甲基）对苯二甲酸（H₂L）为主配体,氯化锌为金属盐,分别与辅助配体4,4''-联吡啶（4,4''-bipy）和2,2''-联吡啶（2,2''-bipy）通过溶剂热法反应合成了配合物[Zn（L）₂（4,4''-bipy）（H₂O）]_n（1）和[Zn（L）（2,2''-bipy）]_n（2）。通过X射线单晶衍射、红外光谱、元素分析、荧光光谱、热重分析等测试手段对其结构和性质进行了表征与研究。结果表明,配合物1是以Zn²⁺为金属节点,L^2-和4,4''-bipy作为连接体相互连接,形成无限延伸的二维网状结构,层与层之间通过O5-H5B…O1氢键作用有序堆积形成三维结构。配合物2以Zn²⁺为金属节点,配体L^2-上的每个羧基都通过双齿螯合的方式桥联锌离子并无限连接形成三维网状结构。     

对苯二甲酸-铕-钇配合物的合成及荧光性质

以对苯二甲酸(H2L)为配体,合成了系列(Eu1-xYx)2L3.3H2O固体粉末配合物.通过元素分析、紫外吸收光谱、X射线衍射和红外光谱确定了配合物的组成和结构,并通过荧光光谱研究了它们的荧光性质.结果表明钇掺入配合物后,能增强Eu3+的特征荧光,当铕与钇的摩尔比为0.05∶0.95时荧光强度最强.     

Synthesis, Structure and Geometrical Calculation of a Novel Co-crystal of {[4-Bromo-2-(benzimidazol-2-yl)phenolato][2- (1-butylbenzimidazol-2-yl)phenolato]zinc(Ⅱ)] and Bis[μ-2- (1- butylbenzimidazol-2-yl)phenolato]- 1κN3: 2κO; 1κO:2κN3-bis{[2-(1-butylbenzimidazol-2-yl)phenolato-κ2N3,O]zinc(Ⅱ)}

The title compound has been synthesized and characterized crystallographically. It is a co-crystal consisting of two different neutral zinc(Ⅱ) complexes with Hbpbm (Hbpbm = 4-bromo-2-(benzimidazol-2-yl)phenol) and Hnpbm (Hnpbm = 2-(1-butylbenzimidazol-2-yl)phenol).One is a monomeric mixed-ligand complex of [Zn(bpbm)(npbm)] 1 and the other a dimer of[Zn2(npbm)4] 2 with their ratio of 2:1. Thus the overall formula for the title compound is 21·2.Adjacent 1 and 2 are connected to each other by intermolecular hydrogen bonding interactions in the lattice. The crystal data: monoclinic, space group P21/c, a= 15.0141(12), b = 20.9941(17), c =18.4686(15) (A), β = 97.445(2)°, V= 5772.4(8) (A)3, Mr= 2429.68, Z = 2, Dc = 1.398 g/cm3,μ = 1.579mm-1, F(000) = 2504, R = 0.0637 and wR = 0.1771 for 6464 observed reflections (I＞ 2σ(Ⅰ)). The geometrical structure for 1 has also been theoretically optimized and compared with the experimental one.     

Syntheses, Crystal Structures and Magnetism of Two New Coordination Polymers [Ni（bix）2Cl2]n and [Co（bix）Cl2]n

The self-assembly reactions of MIICl2 (M = Ni, Co) with the flexible bix ligand [bix = 1,4-bis(imidazole-1-ylmethyl)benzene] yielded a 2D network [NiII(bix)2Cl2]n 1 and a 1D chain [CoII(bix)Cl2]n 2. Their crystal structures have been determined by X-ray single-crystal diffraction analysis. Complex 1 characters a two-dimensional grid-type structure and crystallizes in monoclinic, space group P21/c with a = 7.7231(7), b = 12.7787(9), c = 13.9374(13) , β = 105.419(4)o, C28H28Cl2N8Ni, Mr = 606.19, Ζ = 2, V = 1326.0(2) 3, Dc = 1.518 g/cm3, μ = 0.969 mm-1, F(000) = 628, R = 0.0429 and wR = 0.0783 for 2503 observed reflections (I > 2σ(I)). Compound 2 is a one-dimensional chain and crystallizes in orthorhombic, space group Pbca with a = 11.3696(6), b = 10.2128(6), c = 14.4943(9) , C14H14Cl2CoN4, Mr = 368.12, Z = 4, V = 1683.01(17) 3, Dc = 1.453 g/cm3, μ = 1.334 mm-1, F(000) = 748, R = 0.0317 and wR = 0.0800 for 1778 observed reflections (I > 2σ(I)). Magnetic properties of the title complexes were also investigated.     

镧、钕柠檬酸配合物对纤维素酶活性的影响及其机制的探讨

研究了不同稀土浓度的镧、钕柠檬酸配合物溶液对纤维素酶水解不同纤维素底物的活性的影响规律，并对其作用机制进行了分析：用沉淀法分别合成了镧、钕柠檬酸配合物；用EDTA络合滴定法分析了镧、钕在配合物中的含量；用红外光谱法对镧、钕柠檬酸配合物进行了表征；用DNS试剂法测定了不同稀土浓度的镧、钕柠檬酸配合物溶液对纤维素酶水解不同纤维素底物的酶活性。结果表明：柠檬酸中羧基脱去质子后与镧、钕离子配位，在合适浓度时，两个配合物对纤维素酶水解滤纸、羧甲基纤维素钠、纤维二糖的活性均有最大的激活作用，钕配合物的激活效果好于镧配合物。     

Crystal structure of <Emphasis Type="Italic">tris</Emphasis>(1,10-phenanthroline) iron(II) dinitrate dihydrate

The structure of tris(1,10-phenanthroline)iron(II) dinitrate dihydrate [Fe(phen)₃](NO₃)₂·2H₂O was established by X-ray diffraction analysis. The role of hydrogen bonds in crystal packing is discussed.     

Ultrasonic and Raman Scattering Spectroscopy of Zinc Thiocyanate Complexes in Water at 25<Superscript>∘</Superscript>C: Kinetics of Complex Formation Determined by Multivariate Analysis

Advances have been made recently in broadening the accessible ultrasonic absorption frequency range and improving the detectability of minor species present in solution using Raman spectroscopy. Development of chemometric techniques in these areas needs to keep pace with the improvement of these experimental methods. Refinements in the analysis of ultrasonic and Raman data based on multivariable least squares and factor analysis, respectively, are examined to investigate the kinetics of zinc thiocyanate complex formation in water. Analysis of ultrasonic absorption relaxation spectra verified that the observed process in aqueous Zn(SCN)₂ involves substitution of water from the first coordination shell of Zn²⁺. Use of a multivariable least-squares error surface is described that enhances the reliability of assigned frequencies of ultrasonic absorption maxima. Factor analysis of Raman scattering data provided direct evidence that at least four complex species, such as Zn(SCN)⁺ and Zn(SCN)₂, are simultaneously present in the aqueous zinc thiocyanate solutions.     

Complexation of Ketoconazole by Native and Modified Cyclodextrins

Complexation of ketoconazole (KET), a broad-spectrum antifungal drug, with β- and γ-cyclodextrins (CDs), heptakis (2,6-di-O-methyl)-β-CD (2,6-DM-β-CD), heptakis (2,3,6-tri-O-methyl)-β-CD (TM-β-CD), 2-hydroxypropyl-β-CD (2HP-β-CD) and carboxymethyl-β-CD (CM-β-CD) was studied. The stability constants were determined by the solubility method at pH = 6 and for 2,6-DM-β-CD and CM-β-CD at pH = 5. At pH = 6, the stability constants increased in the order: TM-β-D < γ-CD < 2HP-β-CD < β-CD < CM-β-CD < 2,6-DM-β-CD. At pH = 5, due to the increased ionization of KET, the stability constant with CM-β-CD increased and with 2,6-DM-β-CD decreased. For complexes of KET with 2HP-β-CD and 2,6-DM-β-CD, the thermodynamic parameters of complexation were determined from the temperature dependence of the corresponding stability constants. For β–γ and TM-β-CD complexes, calculations using HyperChem 6 software by the Amber force field were carried out to gain some insight into the host–guest geometry.     

Syntheses and Crystal Structures of [Ni(L)2(NCS)2] and [Co(L)2(NCS)2] (L = Azobis(2-pyridine)

1 INTRODUCTION The synthesis of new organic-inorganic hybrid compounds is a relatively new research area that has developed rapidly in the last several years[1]. Bische- late ligand[2, 3], such as azobis(2-pyridine), is a novel tetradentate ligand expect…