Thermodynamic Stability Research of Metal Complexes with a Tripodal Amide Ligand and Crystal Structure of its Cobalt(Ⅲ) Complex

A new Co（Ⅲ） complex with a tripodal amide ligand [CoL（N3）3] （L = N-acetyl- N＇,N＇-bis-[（2-pyridyl）methyl]-ethylenediamine） has been synthesized and characterized structurally by X-ray diffraction. It crystallizes in orthorhombic, space group Pnma with a = 9.2515（19）, b = 12.729（3）, c = 17.273（4） A, V = 2034.0（7） A3, C16H20CoN13O, Mr = 469.38, Dc = 1.533 g/cm3, μ（MoKα） = 0.884 mm^-1, F（000） = 968, Z = 4, the final R = 0.0392 and wR = 0.0818 for 2430 observed reflections. In the complex, the amide ligand L acts as a tridentate fashion and coordinates to the Co（Ⅲ） ion through three nitrogen atoms, while the other three positions of the Co（Ⅲ） center are occupied by three terminal azide anions. The complex is connected as a 1D chain structure by intermolecular hydrogen bonds between the uncoordinated amide groups. In order to investigate the coordination ability, thermodynamic stability of the ligand L with the first-series transition metal ions （Co（Ⅱ）, Ni（Ⅱ）, Cu（Ⅱ） and Zn（Ⅱ）） has been studied by potentiometric titration, and the results show that the order of their stability constants conforms to the Irving-Williams sequence.

Novel cobalt(Ⅱ) complexes of amino acids-Schiff bases catalyzed aerobic oxidation of various alcohols to ketones and aldehyde

Two cobalt（Ⅱ） complexes 1 and 2 of Schiff bases derived from amino acids were synthesized and used for oxidation of benzyl alcohol with molecular oxygen at different conditions of pH,solvent,temperature and complex/alcohol molar ratio to optimize reaction conditions and to evaluate the catalytic efficiency of new cobalt Schiff base complexes.Under obtained optimum conditions,various alcohols were oxidized to corresponding aldehydes and ketones.

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 Catalytic Activity of Nickel(Ⅱ)and Cobalt(Ⅱ) Complexes Involving Chiral Leucinol

The title nickel complex I and cobalt complex II were obtained separately from the direct reaction of D-（＋）-leucinol with Ni（II） chloride and L-（-）-leucinol with Co（II） acetate tetra- hydrate in anhydrous methanol. The crystal structures of I and II were determined by single-crystal X-ray diffraction and further characterized by elemental analysis and IR. For I： [Ni（C18H45N3O3）]Cl2, orthorhombic, P212121, a = 11.2807（9）, b = 14.7115（11）, c = 16.3580（13） A, V = 2714.7（4） A3, Z = 4, Pcalcd = 1.177 Mg/m3, the final R = 0.0407, and 16539 reflections observed with I 〉 2σ（/）; For II： [Co（C45HI08N6015）], trigonal, R3：H, a = 23.981（3）, b =23.981（3）, c = 10.8925（15） A, γ = 120°, V = 5425.1（14） A3, Z = 3, Pcalcd = 1.002 Mg/m3, the final R = 0.0625 for 16556 observed reflections with I 〉 2σ（I）. The complexes were then used to catalyze the Henry reaction and obtained good catalytic results. The catalytic activity of the complexes was determined by IH NMR. And research is going towards the application to other organic reactions such as cyanosilylation reaction.

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 Cobalt(Ⅱ) Complexes Constructed by Dipyrido[3,2-a:2',3'-c]phenazine and Different Carboxylate Ligands

Two new metal-organic complexes,{[Co2（bptc）（DPPZ）2（H2O）2]·H2O}n 1 and {[Co2（ccm）2（DPPZ）2]·2H2O}n 2,were obtained by the hydrothermal reactions of Co（NO3）2·6H2O with chelating ligand dipyrido[3,2-a：2＇,3＇-c]phenazine（DPPZ） and the corresponding carboxylic acid,namely,3,3＇,4,4＇-benzophenonetetracarboxylic acid（H4bptc） or 2-carboxycinnamic acid（H2ccm）,respectively.The complexes were structurally characterized by single-crystal X-ray diffraction,elemental analyses,IR spectra,and thermal gravimetry.1 presents unique chiral chain structures,which are further consolidated into three-dimensional supramolecular frameworks via noncovalent bonds,such as hydrogen bonding and π-π interactions.2 features infinite double-chain structures,which are connected by strong π-π interactions to result in three-dimensional supramolecular architectures.

Syntheses,Crystal Structures,and Magnetic Properties of Cobalt(Ⅱ) Complexes with 1,1-Cyclohexanediacetic Acid

Two new Co（Ⅱ） coordination polymers,{[Co_3（Hchda）_2（chda）_2（bpp）_2（H_2O）_2]}_n 1 and {[Co（chda）（bpe）（H_2O）]·3H_2O}_n 2（H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis（4-pyridinyl）propane and bpe = 1,2-bis（4-pyridinyl）ethylene）,were hydrothermally synthesized and then characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis（TGA）,and single-crystal X-ray diffraction.Complex 1 possesses an infinite metal-organic layer based on triply bridged linear trinuclear subunits and complex 2 exhibits a square（4,4） grid layer with dangling lateral arms resulting from eight-membered rings above and below the layer.In addition,magnetic properties of complexes 1 and 2 are also given.

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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Fe(Ⅲ)-XG配合物选择性絮凝微细粒赤铁矿与石英及其机理研究

基于金属离子配位理论,将FeCl_(3)·6H_(2)O与黄原胶(XG)按一定比例混合制备Fe(Ⅲ)-XG配合物,用于改善微细粒赤铁矿难沉降、回收效果差的问题。采用沉降实验研究了不同条件下Fe(Ⅲ)-XG对微细粒赤铁矿和石英的选择性絮凝行为,结合动电位、红外光谱和显微镜分析,揭示Fe(Ⅲ)-XG对赤铁矿的絮凝作用机理。矿物絮凝沉降试验结果表明:以黄原胶和Fe(Ⅲ)为絮凝剂,无法实现赤铁矿与石英的选择性絮凝,而黄原胶与FeCl_(3)·6H_(2)O质量比为1︰9时生成的Fe(Ⅲ)-XG配位絮凝剂,对赤铁矿和石英表现出较强的选择性絮凝作用,pH值为6时两者沉降率差异最大,分别为91.50%和39.96%。显微镜观察结果证实,Fe(Ⅲ)-XG作用下,赤铁矿颗粒形成块状絮体,且絮体密实程度更大,而石英颗粒间未发生团聚作用,处于相对分散的状态。Zeta电位、溶液化学计算、吸附量实验与红外光谱分析结果表明:黄原胶主要通过羧酸基团的羰基C=O与Fe^(3+)发生配位作用形成Fe(Ⅲ)-XG配合物,Fe(Ⅲ)-XG在石英和赤铁矿表面吸附方式不同,因而在两种矿物表面吸附量不同。Fe(Ⅲ)-XG中的羟基氧和赤铁矿表面的铁元素发生化学键合特异性吸附在赤铁矿表面,而在石英表面只有微弱的氢键吸附。通过FeCl_(3)·6H_(2)O与黄原胶配位组装可显著提升微细粒赤铁矿选择性絮凝分离效果,为赤铁矿选择性絮凝分选提供新的策略和理论指导。

Molecular and Supramolecular Structures of Manganese(Ⅱ) and Cobalt(Ⅱ) Complexes with 1-Carboxymethylpyridinium-4-carboxylate

Two complexes with a zwitterionic dicarboxylate ligand,Mn（L）2（H2O）4 1 and Co（L）2（H2O）4 2（L = 1-carboxymethylpyridinium-4-carboxylate）,were synthesized and structurally characterized.Complex 1 crystallizes in monoclinic,space group P21 with a = 6.490（2）,b = 19.210（7）,c = 7.813（3） ,β = 92.716（5）o,V = 972.9（6） 3,Z = 2,Mr = 487.28,Dc = 1.663 g/cm3,F（000） = 502,μ = 0.749 mm-1,S = 1.060,the final R = 0.0377 and wR = 0.0893 for 3292 observed reflections with I 2σ（I）.Complex 2 is isomorphous with 1,with a = 6.478（2）,b = 19.052（7）,c = 7.742（3） ,β = 92.690（4）o,V = 954.6（6） 3,Z = 2,Mr = 491.28,Dc = 1.709 g/cm3,F（000） = 506,μ = 0.971 mm-1,S = 1.035,the final R = 0.0425 and wR = 0.0809 for 3289 observed reflections with I 2σ（I）.In the compounds,the mononuclear [M（L）2（H2O）4] units with trans-octahedral coordination geometry are linked into 3D architectures via hydrogen bonding（or second-sphere coordination） involving carboxylate groups and coordinated water molecules.The 3D networks illustrate a 3,8-connected net with Schlfli symbol（4·62）2（42·623·83）.

Synthesis, Crystal Structure, and Fluorescent and Thermal Stability Properties of Two New Cobalt(Ⅱ) Complexes with 2,2’-Bipy as Ligand

Two new cobalt(Ⅱ)complexes[Co2(2,2?-bipy)2(dpa)2(H2O)5]·4H2O(1)and Co(2,2?-bipy)3(SO4)]·7.5H2O(2)have been synthesized with diaphonic acid(H2dpa)and 2,2?-bipyridine(2,2?-bipy)as ligands.In 1,two neighboring cobalt(Ⅱ)ions are linked together by one bridging diaphonic acid group,forming an asymmetric dinuclear structure.1 crystallizes in triclinic,space group P1 with a=9.825(6),b=13.007(8),c=19.586(1)A,α=80.773(1)o,β=77.065(1)o,γ=85.902(1)o,Mr=431.4,V=2406.5(3)A^3,Dc=1.48 g/cm^3,Z=2,μ(Mo Kα)=0.767 mm-1,F(000)=1112,the final R=0.0379 and wR=0.0862.The central cobalt(Ⅱ)ions in 1 and 2 are coordinated with six atoms,forming distorted octahedral coordination geometry.The fluorescence and thermal stability properties of 1 and 2 are also reported.

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.

Cobalt Schiff base complexes: Synthesis characterization and catalytic application in Suzuki–Miyaura reaction

3-Methoxysalicylaldehyde was condensed with the amines 4-aminoacetophenone and 2-amino-5-bromopyridine to obtain Schiff base ligands, 1 and 2, which were coordinated to cobalt salts as complex 1 and complex 2, respectively. The synthesized ligands and complexes were characterized by spectroscopic(FT-IR,UV–Vis,~1H-NMR and mass spectrometry), thermal(TGA) and elemental analysis. The structures of the complexes were verified by evaluating their magnetic susceptibility and spectroscopic evidences. Synthesized complexes were studied for their catalytic activity in the Suzuki–Miyaura cross-coupling of aryl halides with phenylboronic acid. Optimized reaction yields 90% of the cyanobiphenyl for complex 1 and 91% for complex 2 with 0.1 mmol of catalyst loading thereby substantiating the C\\C coupling efficiency of the synthesized complexes, 1 and 2.