Impact of Cr(Ⅲ)complexation with organic acid on its adsorption in silts and fine sands

Trivalent chromium(Cr(Ⅲ))can form stable soluble complexes with organic components,altering its adsorption properties in the water-soil environment.This increases the risk of Cr(Ⅲ)migrating to deeper soils and transforming into toxic Cr(VI)due to the presence of manganese oxides in sediments.In this study,Citric Acid(CA)was selected as a representative organic ligand to prepare and characterize Cr(III)-CA complexes.The characteristics,mechanisms and environmental factors influencing the adsorption of Cr(Ⅲ)-CA on porous media(silts and fine sands)were investigated in the study.The results show that Cr(Ⅲ)coordinates with CA at a 1:1 molar ratio,forming stable and soluble Cr(Ⅲ)-CA complexes.Compared to Cr(III)ions,the equilibrium adsorption capacity of Cr(Ⅲ)-CA is an order of magnitude lower in silts and fine sands.The adsorption of Cr(Ⅲ)-CA in silts and fine sands is dominated by chemical adsorption of monolayers,following the pseudo-second-order kinetic equation and the Langmuir isotherm adsorption model.Varying contents of clay minerals and iron-aluminum oxides prove to be the main causes of differences in adsorption capacity of Cr(Ⅲ)-CA in silts and fine sands.Changes in solution pH affect the adsorption rate and capacity of Cr(Ⅲ)-CA by altering its ionic form.The adsorption process is irreversible and only minimally influenced by ionic strength,suggesting that inner-sphere complexation serves as the dominant Cr(Ⅲ)-CA adsorption mechanism.

Effect of cerium ion(Ⅲ) on corrosion resistance of organic-inorganic hybrid coating on surface of aluminum-tube used in refrigeration equipment

Organic?inorganic hybrid coating on the surface of aluminum-tube used in refrigeration equipment using cerium ion (III) as the additive was fabricated by sol?gel method, and the structure of the coating was confirmed by FT-IR. The results of the characterization show that the corrosion resistance of the coating with 1.5 mmol/L cerium ion (III) gains significant improvement, in which the colour retention time of CuSO4 extends to 500 s, the anti-acid and alkali corrosion rates reduce by 67% and 70% compared with the blank one, respectively, and the salt spray tests also show good corrosion resistance. The electrochemical tests demonstrate that the self-corrosion current density and potential of the sample with hybrid coating are about 2.877×10?7 A/cm2 and?0.550 V, respectively. The metallographic and SEM images show that the hybrid coating is uniform and dense, and the EDS analysis confirms that the coating is mainly composed of Al, Si and Ce elements.

含氮杂环卡宾配体的半三明治铱(Ⅲ)配合物的合成及抗肿瘤转移作用

铱(Ⅲ)抗肿瘤配合物[(η^(5)-C_(5)MeC_(6)H_(4)C_(6)H_(5))Ir(C∧C)Cl]PF_(6)能够选择性杀伤、抑制肿瘤细胞,但其内在的作用机制尚不完全明确.采用细胞划痕法、迁移及侵袭等实验考察了金属铱(Ⅲ)配合物对A549细胞的抗转移能力,采用免疫组织化学法和蛋白印迹法分析NEDD9、β-catenin表达水平.研究结果显示:金属铱(Ⅲ)配合物对A549细胞有明显的抗转移作用,可能通过作用于NEDD9降低肺癌细胞的增殖和转移.同时该金属配合物也可通过诱发β-catenin蛋白的表达,增加细胞膜表面粘性,降低A549细胞的转移能力.

Thermal Decomposition Kinetics and Mechanism of Tb(Ⅲ) m-Methylbenzoate Complex with 1,10-Phenanthroline in Static Air Atmosphere

The thermal behavior of [Tb_2( m -MBA)_6(phen)_2](H_2O)_2( m -MBA=C_8H_7O_2, methoxybenzoate; phen=C_ 12 H_8N_2, 1,10-phenanthroline) in static air atmosphere was investigated by means of TG-DTG and DTA methods. The thermal decomposition of the title compound takes place mainly in two steps. The intermediate and the residue for each decomposition were identified by the TG curve. By the kinetic method of processing thermal analysis data put forward by Malek et al ., it is defined that the kinetics model for the first-step thermal decomposition is SB( m,n ).

Synthesis of Eu(Ⅲ) and Tb(Ⅲ) Complexes with New Aryl Amide Type Tetrapodal Ligand and Their Luminescence Properties

A new aryl amide type tetrapodal ligand L (1, 1, 1, 1 tetrakis-{[(2 benzylaminoformyl) phenoxyl]methyl}methane) and its europium and terbium nitrate complexes were synthesized. The luminescence properties of these complexes were also studied.

Catalytic performance of cerium iron complex oxides for partial oxidation of methane to synthesis gas

The cerium iron complex oxides oxygen carrier was prepared by the co-precipitation method. The reactions between methane and lattice oxygen from the complex oxides were investigated in a fixed micro-reactor system. The reduced oxygen carder could be re-oxidized by air and its initial state could be restored. The characterizations of the oxygen carders were studied using XRD, O2-TPD, and H2-TPR. The results showed that the bulk lattice oxygen of CeO2-Fe2O3 was found to be suitable for the partial oxidation of methane to synthesis gas. There were two kinds of oxygen species on the oxygen carrier： the stronger oxygen species that was responsible for the complete oxidation of methane, and the weaker oxygen species （bulk lattice oxygen） that was responsible for the selective oxidation of methane to CO and H2 at a higher temperature. Then, the lost bulk lattice oxygen could be selectively supplemented by air re-oxidation at an appropriate reaction condition. CeFeO3 appeared on the oxygen carrier after 10 successive redox cycles, however, it was not bad for the selectivity of CO and H2.

Synthesis,Fluorescence and Magnetic Properties of a New Europium(Ⅲ)Complex Eu(C14H9O3)2(C12H8N2)2(NO3)

A new europium(III)complex Eu(CHO)(CHN)(NO)has been synthesized with 2-benzoylbenzoic acid and 1,10-phenanthroline as ligands.Crystal data for the complex are as follows:monoclinic,space group P2/c,a=9.6733(6),b=22.9521(14),c=19.7701(12)?,β=94.9800(10)o,V=4372.8(5)?~3,D=1.557 g/cm~3,Z=4,μ(Mo Kα)=1.501 mm,F(000)=2064,the final R=0.0214 and w R=0.0510.The Eu(III)ion is coordinated by ten atoms to give a bicapped square antiprism coordination geometry.The complex shows two intense fluorescence emission bands arising from the transitions of Eu:~5D→~7F(594 nm)and ~5D→~7F(618 nm).In addition,its XT decreases from 1.29767 cm~3?mol?K at 300 K to 0.01531 cm~3?mol?K at 2 K.

Intercalation Assembly, Characterization and Luminescent Properties of Novel Supramolecular Composite Materials, Tb(Ⅲ) Complex with Tetrapodal Ligand-Montmorillonite

Two kinds of Tb（ Ⅲ ） complexes with tetrapodal ligand, [TbL（NO3）]^3＋ and [TbL]^3＋ （L： 1,1, 1＇, 1＇-tera （ 2-pyridinecarboxylester ）-di （ trimethylpropane）） were intercalated into the interlayer space of montmorillonite （MT） by ion exchange and coordination reaction of L with the Tb^3＋ ion existing in the interlayer space of Tb-MT respectively. The obtained luminescent supramolecular composite materials, [ TbL （NO3） ]^2＋-MT and [TbL]^3＋-MT were characterized by elemental analysis, XRD, FT-IR, UV-vis and thermal analysis. At the same time, the luminescent properties of the materials were also studied. The results show that the intercalated materials with regular layered structure, good thermal stability and the interlayer spacing （d001） approximates to the size of the complex ions which are located in the interlayer space of MT in the form of a monolayer.

Investigation on Molecular and Crystal Structures of Metal Complexes with Aminopolycarboxylic Acids——Synthesis and Structure of K[In~Ⅲ(EDTA)(H_2O)]·2H_2O

The title complex was synthesised and its molecular and crystal structures were determined by single crystal X ray reflection structure analysis. The crystal data are as follows: K[In Ⅲ(EDTA)(H 2O)]·2H 2O (EDTA=ethylene diamine N, N, N′, N′ tetraacetate), Monoclinic, C c space group, a=0.9096(2) nm,b=1.1996(2) nm, c =1.5144(3) nm, β =99.40(3)°, V =1.6302(6) 3, Z =3, D c=1.498 g·cm -3 , μ =1.325 mm -1 , F (000)=726, R =0.0320 and R W=0.0903 for 2315 observed independent reflections. The complex anion [In Ⅲ(EDTA)(H 2O)] - has a seven coordinate pseudo pentagonal bipyramidal (PB D 5h ) structure, in which the EDTA serves as a hexadentate ligand with two N atoms and four O atoms and one water molecule (H 2O) directly coordinated to the central metal ion In Ⅲ as a seventh ligand. 〓〓

Synthesis and Characterization of Some Lanthanide(Ⅲ) Complexes with 4-[N-(2-methoxybenzylimine)formyl]-2, 3-dimethyl-1-phenyl-3-pyazolin-5-one

A series of seven novel lanthanide（Ⅲ ） nitrato complexes with 4-[ N-（2-methoxybenzylimine）formyl] 1-2, 3- dimethyl-1-phenyl-3-pyazolin-5-one （2mbfa）, were synthesized. These complexes were characterized by elemental analysis, molecular mass determination, conductance and magnetic moment measurements, IR, UV-visible, and ^13CNMR spectral studies, In these complexes, the Schiff base, 2mbfa, acts as neutral bidentate ligand by utilizing the carbonyl oxygen and azomethine nitrogen as donor sites. All the three nitrate ions are also coordinated unidentately with 7 coordination for the lanthanide（Ⅲ） ions with a tentative monocapped octahedral geometry for the complexes. All the seven lanthanide（Ⅲ） complexes have a general formula, [ Ln（2mbfa）：（NO3）3 ].

Crystal Structure and Fluorescent Study of a Binuclear Europium(Ⅲ) Complex

A novel binuclear Eu（Ⅲ） complex [Eu2（dpa dioxide）2（NO3）4（bpdioxide）-（EtOH）] （dpa dioxide = di-2-pyridylamine N,N＇-dioxide, bpdioxide = 2,2＇-bipyridine N,N＇-dioxide） has been synthesized and it exhibits strong and sharp fluorescent emission at 614 nm under UV radiation of 245 nm at room temperature. X-ray structural determination indicates two independent Eu（Ⅲ） ions in the structure with different EuO8N and EuOgN environments. The compound crystallizes in the triclinic system, space group P1, with a = 10.8089（7）, b = 11.4670（8）, c = 17.1440（12） A, α = 92.834（2）, β = 93.854（3）, γ = 95.433（2）°, Z = 2, Dc = 1.876 g/cm3, V= 2107.3（2） A3, F（000） = 1168.0, the final R = 0.032 and wR = 0.086 for 6331 observed reflections with I 〉 2σ（I）.

Syntheses and Magnetic Properties of Cu（Ⅱ）－RE（Ⅲ） Heterobinuclear Complexes with N，N′－Bis（3－carboxyisalicylidene）－trimethylenediamine

ine heterobinuclear complexes of Cu (Ⅱ)-RE (Ⅲ) with N, N′-bis-(3-car-boxylsalicylidene ) trimetliylenediamine (TS) were syntliesized and characterized bymeans of elemental analyses, molar conductivity, thermogravimetry,IR and elec-tronic spectra. The measurements of variable-temperature magnetic susceptibilitysliow that there exists only a very weak antiferromagnetic spin exchange interactionbetween the ions of Cut(Ⅱ) and RE(Ⅲ) in CuRETSCI . 3H_2O.

Synthesis and Fluorescent, Magnetic and Thermal Stability Properties of a New Europium（Ⅲ） Complex Eu2(C15H11O3)6(C12H8N2)2

A new europium（Ⅲ） complex Eu2(C15H11O3)6(C12H8N2)2 has been synthesized with 2-（4-Methylbenzoyl）benzoic acid and 1,10-phenanthroline as ligands. Crystal data for the complex are as follows: monoclinic, space group P21/n, a = 15.1238（5）, b = 13.5928（4）, c = 22.9840（7） ?, β = 104.132（3）o, V = 4582.0（2） ?3, Dc = 1.522 g/cm3, Z = 4, μ（Mo Kα） = 1.433 mm-1, F（000） = 2128, the final R = 0.0447 and wR = 0.0826. The Eu（Ⅲ） ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry. The complex shows two intense fluorescence emission bands arising from the transitions of Eu3+: 5 D0 → 7 F1（594 nm） and 5 D0 → 7 F2（617 nm）. The complex is an antiferromagnetism system in the range of 150～300 K. Also reported in the paper is the thermal stability property of the title complex.

Synthesis, Crystal Structure and Fluorescence Properties of a Terbium(Ⅲ) Complex with Biphenyl-2,3,3’,5’-tetracarboxylic Acid

A new terbium complex based on biphenyl-2,3,3’,5’-tetracarboxylic acid（H4bptc） has been synthesized, {[Tb（Hbptc）（H2O）4]×H2O}n（1）. Its structure was determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra and TG analyses. Title complex crystallizes in monoclinic, space group P21/n with a = 14.090（2）, b = 8.0824（13）, c = 15.5591（17） ?, V = 1775.4（5） ?3, Mr = 576.22, Dc = 2.156 g/cm3, μ（Mo Kα） = 4.059 mm-1, F（000） = 1128, Z = 4, the final R = 0.027 and w R = 0.0726 for 3296 observed reflections（I > 2σ（I））. Complex 1 exhibits a 2 D layer structure, and such layers are further united together into a three-dimensional supramolecular structure through π···π interaction and intricate hydrogen bonding. The fluorescence excitation and emission spectroscopy of 1 showed that H4 bptc is a kind of highly efficient sensitizer for terbium（Ⅲ） ion. The title complex also displays efficient ligand sensitized luminescence in the visible region with long lifetime of 2.02 ms in the solid state.

Hydrothermal Syntheses and Crystal Structures of Three Lanthanide(Ⅲ)Complexes Based on Carboxyl Derivatives of 1,10-Phenanthroline

Three lanthanide（III） complexes [Ln（4-NCP）（1,4-BDC）]n·xn H2O（Ln = Pr（1）, Sm（2）, Nd（3）. 4-HNCP = 2-（4-carboxyphenyl）imidazo（4,5-f）（1,10）phenanthroline, 1,4-H2 BDC = benzene-1,4-dicarboxylic acid） have been hydrothermally synthesized and characterized via elemental analysis, infrared spectrometry and single-crystal X-ray diffraction. Structural analyses revealed that complexes 1~3 possess similar porous three-dimensional frameworks with the point symbol {4^（12）·6~3}. Meanwhile, complexes 1~3 exhibit excellent thermal stabilities and complex 2 exhibits characteristic luminescent property.

Synthesis and Crystal Structure of a Binuclear Gadolinium（Ⅲ） Complex Bridged by Cucurbit[6]uril

A new cucurbit[6]uril bridsed binuclear complex {[Gd（H2O）6]2[Q6（H2O）]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium（Ⅲ） ions, in which each gadolinium（Ⅲ） ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complcx to threedimensional supramolecular structure.

Stability Constants and Fluorescence of Terbium(Ⅲ) Complexes with Polyaminopolycarboxylates in Aqueous Solution

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Synthesis and the Fluorescent, Magnetic and Thermal Stability Properties of a New Terbium（Ⅲ） Complex Tb(C20H14O3N)3(C12H8N2)（H2O）·H2O

A new terbium(Ⅲ complex Tb(C20H14O3N)3(C12H8N2)（H2O）·H2O has been synthesized with 2-diphenylanine carbonyl benzoic acid and 1,10-phenanthroline as ligands. Crystal data for the complex are as follows: triclinic, space group P1, a =11.6034（6）, b = 16.2465（8）, c = 16.4427（8） ?, α = 73.168（5）o, β = 88.655（4）o, γ = 82.865（4）o, V = 2943.7（3） ?3, Dc = 1.494 g/cm3, Z = 2, μ（MoK α） = 1.272 mm-1, F（000） = 1348, the final R = 0.0535 and w R = 0.0809. The Tb（Ⅲ） ion is coordinated by nine atoms to give a monocapped square antiprism coordination geometry. The complex shows four fluorescence emission bands arising from the transitions of Tb3+: 5D4 → 7F6（491 nm）, 5D4 → 7F5（546 nm）, 5D4 → 7F4（585 nm） and 5D4→7F3（621 nm）. Also reported are the magnetic and thermal stability properties of the complex.

Synthesis, Structure and Properties of a Two-dimensional Samarium(Ⅲ) Complex of 1,3-Benzenedicarboxylic Acid and 1,10-Phenanthrolin

The title complex [Sm2（bdc）3（phen）2]n （1, H2bdc = 1,3-benzenedicarboxylic acid, phen = 1,10-phenanthrolin）, a new samarium（III） complex based on ligand H2bdc and 1,10-phen- anthrolin, has been hydrothermally synthesized and characterized by elemental analysis, FT-IR, and single-crystal X-ray diffraction. The crystal structure reveals that the Sm（1） centre adopts an eight-coordinated distorted square anti-prism coordination geometry, while the Sm（2） centre adopts a nine-coordinated distorted monocapped square prism coordination geometry. The ligand bdc2- takes two different connecting modes and links the Sm（llI） centers to give rise to a 2D network structure. Further, 2D layers of 1 are connected together to form a 3D structure through C-H-O hydrogen bonding interactions. The luminescent property and thermal stability of complex 1 are studied. 1 belongs to the triclinic system, space group P1 with a = 10.7367（5）, b = 14.3750（7）, c = 13.7505（3）A, a = 92.8840（10）, β = 104.4010（10）, ）, = 98.1400（10）°, Z= 2, V= 2143.44（18） A3, Mr = 1153.44, Dc = 1.787 g/cm3, F（000） = 1128,μ= 2.784 mm-1, the final R = 0.0279 and wR = 0.0720 for 8226 observed reflections with 1 〉 2σ（I）.

Kinetics and Mechanism of Iridium(Ⅲ)-Catalyzed Oxidation of Ethanol Amine by Cerium(Ⅳ) in Sulfuric Acid Media

In this study, the kinetics and mechanism of the iridium（ Ⅲ ） -catalyzed oxidation of ethanol amine（EAN） by cerium（Ⅳ） in a sulfuric acid medium was investigated using titrimetric technique of redox in a temperature range of 298--313 K. It was found that the reaction is of first order with respect to Ce（ Ⅳ ） and It（ Ⅲ ）, and a positive fractional order with respect to EAN. It was also found that the pseudo-first-order （ [EAN ] 〉〉 [ Ce （ Ⅳ） ] ） rate constant koba decreases with the increase of [ H^＋ ] and [ HSO^-4 ]. Under the protection of nitrogen gas, the reaction system can initiate the polymerization of acrylonitrile, indicating the generation of free radicals. On the basis of the experimental results, a suitable mechanism was proposed. From the dependence of koba on the concentration of hydrogen sulfate, Ce（SO4）2 was found to be the kinetically active species. The rate constants of the rote-determining step together with the activation parameters were evaluated.