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.

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 ].

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.

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.

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

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Eu(Ⅲ) complexes involving 1,3,5-triazine diphosphine oxides

The 1,3,5-triazine diphosphine oxide ligands with donor-acceptor properties formed strong complexes with europium（Ⅲ） ion in acetonitrile. Spectrophotometric titrations and mass spectra indicated that two ligands coordinated to one europium ion. The stability constants varied from 11.64 to 14.60 （log 13）. Binary complexes exhibited rather weak luminescence in solution. 1,3,5-triazine diphosphine oxides engaged as co-ligands in Eu（Ⅲ） （2-thenoyltrifluoroacetonate）3 complex contributed to the overall photoluminescence and allowed for excitation with longer wavelengths than the parent complex.

Synthesis,Structure and Magnetic Properties of Novel Carboxylato-bridged Pentanuclear Copper(Ⅱ)-Lanthanoid(Ⅲ)Complexes

Six novel pentanuclear complexes [Cu 3Ln 2(ClCH 2CO 2) 12 (H 2O) 8]·2H 2O (Ln=La, Pr, Sm, Gd, Dy, or Er) were synthesized by the reaction of chloroacetic acid with Cu and Ln ions in aqueous solutions. The X ray crystallography established the structure of the Gd complex, which contains a pair of quadruply acetato bridged CuGd dinuclear subunits, and each of them is linked to the central Cu atom by a single acetato bridge. The coordination sphere of each Gd atom is completed by three aqua ligands [Gd-O=0.242 8(5)-0.244 4(4) nm] to form an 8 coordinated distorted square antiprism. The central Cu atom is coordinated by two oxygen atoms from the two bridging acetato groups and two oxygen atoms from the two monodentate acetato groups in a slightly distorted square planar fashion, while each terminal Cu atom is coordinated by the four acetato oxygen atoms at the basal plane and an aqua ligand at the apical position to form a square pyramid. The variable temperature (4 320 K) magnetic susceptibility data of the Gd complex were measured, and fitted to the Curie Weiss law with C =16.38 K cm 3·mol -1 and θ =-1.55 K, indicating very weak antiferromagnetic interaction.

Microwave assisted synthesis, spectroscopic, thermal, and antifungal studies of some lanthanide(Ⅲ) complexes with a heterocyclic bishydrazone

A bishydrazone formed by the condensation of isatinmonohydrazone and salicylaldehyde reacted with lanthanide（Ⅲ） chloride to form complexes of the type [Ln（HISA）2Cl3], where, Ln=La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, or Gd（Ⅲ） and HISA= [（2-hydroxybenzaldehyde）-3-isatin]bishydrazone. Both reactions were carried out under microwave conditions. The ligand and the metal complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements, UV visible, infrared, far infrared, and proton NMR spectral data. The ligand acted as neutral tridentate, coordinating through the carbonyl oxygen, azomethine nitrogen, and phenolic oxygen without deprotonation. The ligand and lanthanum（Ⅲ） complex were subjected to X-ray diffraction studies. The X-ray diffraction pattern of ligand exhibited its crystalline nature and that of the lanthanum（Ⅲ） complex indicated its amorphous character. The thermal decomposition behaviour of the complex, [La（HISA）2Cl3], was examined in the temperature range of 40-800 ℃ using TG, DTG, and DTA. The ligand and the metal complexes were screened for their antifungal activities.

Preparation,Characterization and Properties of Two New Lanthanide(Ⅲ)-5-(2-pyridyl)tetrazolate Complexes

Two new mononuclear lanthanide（Ⅲ） complexes Ln（pytz）3（H2O）3·（H2O）3.5[Ln=Tb（1）;Eu（2）;Hpytz=5-（2-pyridyl）tetrazole] were synthesized by reacting Hpytz with the corresponding lanthanide（Ⅲ） ions and characterized.The single crystal X-ray diffraction analysis reveals that complexes 1 and 2 are isostructural and the lanthanide（Ⅲ） ions in both complexes 1 and 2 are nine-coordinated,with three oxygen atoms of three coordination water molecules and six nitrogen atoms of three pytz ligands,forming a monocapped square antiprism.Extensive hydrogen bonds exist,resulting in a three-dimensional supramolecular network structure by hydrogen-bonds in both complexes 1 and 2,respectively.Complex 1 exhibits typical green fluorescence of Tb（Ⅲ） ion and complex 2 red fluorescence of Eu（Ⅲ） ion,in solid state at room temperature.

Degradation of Azo Dyes by Photocatalysis of Fe(Ⅲ)-oxalate Complexes/H_2O_2 in Aqueous Non-ionic Surfactant Triton X-100 Solution

Two azo dyes,C.I.Reactive Red 195(RR195)and C.I.Acid Black 234(AB234)were degraded by photocatalysis of Fe(Ⅲ)-oxalate complexes/H2O2 in aqueous non-ionic surfactant,Triton X-100(TX-100)solution.Some factors affecting the dye degradation such as TX-100 concentration,irradiation intensity,and sodium chloride were investigated.The interaction and competition between dye and TX-100 during the degradation were also examined using spectrophotometry and maximum bubble pressure method,respectively.The results indicated that TX-100 showed a significant reduction effect on degradation of two azo dyes,but which was largely confined to TX-100 concentration below the Critical Micellar Concentration(CMC).And the reduction was considerably decreased above the CMC,especially in the case of AB234.Moreover,the reducing effect of TX-100 on dye degradation almost did not vary with irradiation intensity.And the impact of sodium chloride on dye degradation was limited by the addition of TX-100.

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.

Electric Conductivity Study of o-Substituted Phenoxo Iron （Ⅲ） Complexes

The coordination nature of a number of substituted sodiumphenoxides to iron （Ⅲ） ion has been studied. The o-nitrosodiumphenoxide was found to have different coordination behaviour from that the sodium salts of salicylic acid and methylsalicylate showed. The structure of the complexes, the number of the ligands being coordinated to the metal ion, has also been determined by titration, uv-vis spectroscopy, atomic absorption and the flame test. In addition, other sodium phenoxides were also involved in this study for comparison. An electric conductivity study on the resulting complexes was carried out and all complexes were found to be semiconductors.

Synthesis, Characterization and Antibacterial Activity of New Ln(Ⅲ) Complexes with an Unsymmetrical Schiff Base Ligand

A new unsymmetrical Schiff base ligand (H2LLi) was synthesized using L-lysine, salicylaldehyde and 2-hydroxy-1-naphthaldehyde. Three solid metal complexes of this ligand \[Ln(H2L)(NO3)\] NO3·2H2O (Ln=La, Sm, Ho) have been prepared and characterized by elemental analyses, IR spectra, UV spectra, TG-DTG and molar conductance. The antibacterial activities of the ligand and its complexes are also studied. The antibacterial experiments indicate that the ligand and its complexes possess antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis and that the complexes have higher activity than those of the ligand.

Synthesis and fluorescence properties of Tb(Ⅲ) complexes with pyridine-2,6-dicarboxylic acid derivatives

Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and characterized by infrared spectrometry, 1H nuclear magnetic resonance, elemental analysis and gas chromatograph-mass spectrometry. The ligand synthetic route was optimized. The fluorescence properties of the complex in solid state, in different kind of solvents and in solutions with different pH values were investigated in detail. The results show that the yields of DSPDA and 4-SPDA reach over 78% by Wittig-Horner reaction and other eight pyridine-2, 6-dicarboxylic acid derivatives with different substituents on pyridine ring, and their complexes with Tb(Ⅲ) are also obtained. The fluorescence intensities of the complexes with electron-donating groups are more intense than those of the complexes with electron-withdrawing groups on pyridine ring; fluorescence intensities of the complexes are the strongest in neutral solution (pH=7), and the less the dipole moment of solvent molecule is, the stronger the fluorescence intensity is. It is found that the two ligands (4-APDA and DSPDA) are the good sensitizers for Tb(Ⅲ) ion.

Oligomannuronate-Chromium (Ⅲ) Complex Ameliorates Insulin Resistance in C57BL/KsJ-db/db Mice

Diabetes mellitus is the most common metabolic disease and its prevalence is increasing in many countries year by year.More than 90% of diabetes patients are type 2 diabetes,which is caused by insulin resistance and beta-cell dysfunction.In this paper,the oligomannuronate-chromium(III)complex(OM2)was prepared and its effect and mechanism on attenuating insulin resistance in diabetic C57BL/KsJ-db/db mice were studied.The results indicated that oral intake of OM2(50 mg kg-1d-1)for 42 d decreased blood glucose and lipid concentration,which was associated with the reduced serum insulin concentration and insulin resistance.According to western blot assay,OM2 could activate AMPK pathway to regulate glycogen synthesis,gluconeogenesis and lipid metabolism in the liver,and attenuate the hyperglycemic symptom in db/db mice.The effects of OM2 on attenuating insulin resistance were com-parable to that of the established antidiabetic drug metformin,and OM2 showed less adverse effect than metformin in vivo.Based on the effectiveness and low toxicity,OM2 may potentially be used for prevention and treatment of type 2 diabetes mellitus.

Synthesis,Crystal Structure and Interaction with DNA of a Novel Chromium(Ⅲ) Complex Containing Salicylaldehyde Semicarbazone

The novel chromium（Ⅲ） complex with salicylaldehyde semicarbazone was synthesized and characterized by IR spectra and single-crystal X-ray diffraction analysis. The crystal belongs to the orthorhombic system, space group Pbca with a = 8.9849（13）, b = 12.0475（16）, c = 34.522（5）A, V = 3736.9（9）A3, Z = 8, C16H18C1CrN6O5, Mr= 461.81, De= 1.642 g/cm^3, F（000） = 1896,A（MoKα） = 0.799 mm^-1, the final R = 0.0370 and wR = 0.0827 for 2908 observed reflections with I 〉 2σ（I）. The interaction between the chromium（Ⅲ） complex with calf thymus DNA （Ct-DNA） has been investigated by absorption spectroscopy, fluorescence spectroscopy and viscosity measurements. The results indicated that the complex was bonded to Ct-DNA through a non-classical intercalative mode.

Photodegradation of bisphenol A in Fe(Ⅲ)-oxalate complexes solution

The aqueous photodegradation of bisphenol A （BPA） in the presence of Fe（Ⅲ）-oxalate complexes （Fe（Ⅲ）-Ox）, which are common compositions of natural water, was investigated in this study. BPA underwent rapid indirect photolysis in Fe（Ⅲ）-Ox solution under simulated solar irradiation, proceeding pseudo-first-order kinetics. The photolysis rate increased with decreasing pH or initial BPA level and increasing Fe（Ⅲ）/oxalate concentration ratio. Hydroxyl radicals （·OH）, which were generated from the photochemical processes of Fe（Ⅲ）-Ox complexes and contributed to the photooxidation of BPA, were determined by molecular probe and electron spin resonance （ESR） methods with the steady-state concentration of 2.56 × 10^-14 mol/L. Superoxide anion radical （O2^·-） was considered as the precursor of. OH and qualitatively determined by adding nitro blue tetrazolium as well as ESR experiments. Based on the structural analysis of the intermediate photoproducts of BPA in Fe（Ⅲ）-Ox complexes solution, the possible degradation pathways of BPA were proposed, involving ·OH addition, alkyl scission and alky oxidation. The results indicate that the photochemical reactivity of Fe（Ⅲ） may affect the environmental fate of BPA in natural water significantly.

Syntheses and Magnetism of Binuclear Tb(Ⅲ)-Tb(Ⅲ)Complexes with Dianion of Chloranilic Acid as Bridging Ligand

The syntheses, spec(?) complexes are of significance for understanding mechanisms of magnetic interaction between metal ions and the exploitation of the synthesis of molecular magnetic materials. There were a few works reported previously on the syntheses and magnetic in-