Synthesis and spectroscopic characterization of fluorescent solid rare-earth complexes with hydroxamic acids

The complexes RE_2(DHYA)_3 centre dot nH_2O in the title bar were synthesizedthrough some reactions of trivalent rare-earth ions. In the process of synthesis, dihydroxamicacids were taken as ligands while the alcohol was taken as a solvent. The ligands includedadipylhydroxamic acid (ADHA), p-phthalichydroxamic acid (PPHA), oxalohydroxamic acid (OXHA),butadihydroxamic acid (BDHA), o-phthalichydroxamic acid (OPHA), benzoylhydroxamic acid (BHA), etc.Measured at 25 deg C, the molar conductances in various modes are 13.00-21.05 S centre dot cm^2centre dot mol^(-1), which shows that rare-earth complexes are nonelectrolytes and the hydroxaminogroups of the complexes have taken part in bonding. Infrared spectra, ultraviolet spectra, nuclearmagnetic resonance (~1HNMR) spectra, and fluorescence spectra were used to investigate thecomplexes. Experiments have proved that the complexes of En^(3+)and Tb^(3+) with aromatic hydroxamicacids have good fluorescent characteristics.

Synthesis,Crystal Structure and Fluorescence Property of a New Trinuclear Nickel(Ⅱ) Complex Bridged by 2,6-Pyridine Dicarboxylic Acid

A new trinuclear nickel complex,[Ni3（pdc）3（2,2＇-bipy）3（H2O）2]·2H2O（H2pdc = pyridine 2,6-dicarboxylic acid,2,2＇-bipy = 2,2＇-bipyridine） has been hydrothermally synthesized and characterized by IR,elemental analysis and X-ray diffraction methods.Crystal data for this complex：monoclinic,space group P21/n,a = 21.206（4）,b = 10.002（2）,c = 28.066（6）,β = 108.18（3）°,C51H41N9Ni3O16,Mr = 1212.06,V = 5.656（2） nm3,Dc = 1.423 g·cm-3,μ（MoKα） = 1.062 mm-1,Z = 4,F（000） = 2488,GOOF = 1.034,the final R = 0.0543 and wR = 0.1237 for 6149 observed reflections with Ⅰ 〉 2σ（Ⅰ）.In the complex,three nickel（Ⅱ） ions are bridged by the pyridine 2,6-dicarboxylic acid groups,and all nickel（Ⅱ） ions are seven-coordinated by nitrogen atoms of 2,2＇-bipyridine and pyridine 2,6-dicarboxylic acid and oxygen atoms from pyridine 2,6-dicarboxylic and water to adopt a severely distorted pentagonal bipyramidal geometry.The emission and excitation peaks of the complex in ethanol solutions are located at 336 and 316 nm,respectively.

Synthesis, Crystal Structure and Properties of a Europium Complex with 3-Iodobenzoic Acid and 2,2'-Bipyridine

The complex [Eu（3-IBA）3·2,2＇-bipy]2 was synthesized from 3-iodobenzoic acid （3-HIBA）, 2,2＇-bipyridine （2,2‘-bipy） and EuCl3·6H2O by hydrothermal synthesis, and its crystal structure was determined by X-ray single-crystal diffraction. It is of triclinic, space group Pi, with a = 10.958（2）, b = 12.311（3）, c = 12.556（3） A, α = 81.549（3）, β = 82.404（4）, γ = 78.348（3）°, Mr = 1049.15, V= 1631.7（6） A3, Z = 1, Dc = 2.135 g/cm^3, F（000） = 980, 2（MoKa） = 0.71073 A,μ（MoKa） = 4.804 mm^-1, the final R = 0.0329 and wR = 0.0723 for 4640 observed reflections with I 〉 2σ（I）. The Eu（Ⅲ） ion is eight-coordinated and two Eu（Ⅲ） ions are held together by four 3-iodobenzoate groups in the bidentate bridging mode. The complex was characterized by DTA-TG, IR, UV and fluorescence spectra.

Synthesis,Crystal Structure and Antitumor Activity of a Novel Zn(Ⅱ)Complex with 2-(Nicotinoyloxy)acetic Acid Ligand

A novel Zn（Ⅱ） complex, [ZnL2（H2O）4]·H2O（1, HL = 2-（nicotinoyloxy）acetic acid）, was synthesized using Zn（OAc）2·2H2O and 2-（nicotinoyloxy）acetic acid as raw materials. Its structure has been elucidated by elemental analysis, IR and single-crystal X-ray diffraction. The structural analysis revealed that complex 1 crystallizes in triclinic, space group P1 and the Zn（Ⅱ） atom is six-coordinated with two N atoms from two different 2-（nicotinoyloxy）acetate anion ligands and four O atoms from coordinated water molecules. Complex 1 forms a 3D network structure by O–H···O hydrogen bonds. The antitumor activities of 2-（nicotinoyloxy）acetic acid ligand and its Zn（Ⅱ） complex were evaluated against human lung adenocarcinoma A549 cells, human hepatoma SMMC-7721 cells and human colon carcinoma Wi Dr cells.

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.

Synthesis,Structure,and Surface Photo-electric Properties of a New Zn(Ⅱ)Coordination Complex Constructed from 2-(1H-benzotriazol-1-yl)acetic Acid and 1,10-Phenanthroline Ligands

A new binuclear Zn^Ⅱ coordination complex,Zn2（bta）（phen）2（Cl）3（1,Hbta = 2-（1Hbenzotriazol-1-yl）acetic acid and phen = 1,10-phenanthroline）,has been synthesized and characterized by single-crystal X-ray diffraction,IR spectroscopy,elemental,and photoluminescent analysis.Complex 1 crystallizes in triclinic system,space group P1 with a = 9.3040（19）,b = 10.694（2）,c =16.841（3） A°,α = 101.18（3）,β = 105.77（3）,γ = 91.72（3）°,V= 1575.8（5） A°3,C（32）H（22）Zn2Cl3N7O2,Mr =773.66,Dc = 1.631 g/cm^3,Z = 2,F（000） = 780,μ = 1.820 mm^-1,the final R = 0.1238 and wR =0.1131.X-ray diffraction analyses indicate that 1 displays two crystallographic independent Zn^Ⅱmetal centers with a distorted tetragonal pyramidal（ZnN4O） and a tetrahedral（ZnNCl3） geometries,respectively.The phen serves as a common N,N＇-bidentate ligand,and the bta^- as a unique N,O-bridged ligand in 1.In the crystal,1 forms a stable 3D supramolecular architecture by trifurcated hydrogen bonding C-H…C1 interactions and C-H…π,π…π stacking.1 showed photo-electric conversion properties.

Synthesis and Characterization of Lanthanide Complexes Involving Cyclopentadienyl and Benzohydroximic Acid Ligand

By the reaction of Cp 3Ln with HL(Cp=η 5 C 5H 5, cyclopentadienyl; Ln=Yb, Tm, Er, Ho, Dy, Gd, Pr; HL=benzohydroximic acid), seven new complexes of the general formula Cp 2LnL were synthesized. All the complexes were characterized by elemental analysis, infrared spectra, and mass spectra. Based on these data, the probable structure was proposed.

Synthesis and Crystal Structure of 2,2'-Dihydroxy-[1,1']binaphthalenyl-3,3'-bis-hydroxamic Acids

The first synthesis and structural characterization by X-ray crystallography of racemic 2,2＇-dihydroxy-[1,1＇]binaphthalenyl-3,3＇-bis-hydroxamic acids were reported.The com-pound（C28H30N4O8,Mr = 550.56） crystallizes in orthorhombic system,Fdd2 space group with a = 13.055（3）,b = 34.871（7）,c = 12.570（3） ,V = 5722（2） 3,Z = 8,Dc = 1.278 g/cm3,λ = 0.71073 ,μ（MoKα） = 0.095 mm-1,F（000） = 2320,S = 1.021,R = 0.0349 and wR = 0.0802 for 1757 observed reflections with I 〉 2σ（I）.The N-H and O atom are involved in two-dimensional intermolecular hydrogen bond nets,which further stabilize the structure.

Synthesis and Characterization of Lanthanum Complexes with Amino Acid Schiff Base

Six new complexes of lanthanum with amino acid Schiff base ligands, A-F, were prepared in methanol-aqueous solution. The composition and properties of the title complexes were characterized by elemental analysis, molar conductance, infrared, electronic spectra, H-1 NMR, thermogravimetric and differential thermal analysis.

SYNTHESIS AND STRUCTURE DETERMINATION OF NEODYMIUM COMPLEXES WITH CYCLOHEXANECARBOXYLIC ACID

Two complexes,NdL_3·2C_2H_5OH and NdL_3·2H_2O where L=cyclohexane-carboxylate anion,were synthesized and the structure of the former was determined by the single-crystal X-ray diffration method. The crystal is triclinic,Pspace group with the cell parameters:a=1.2385(6),b=1.2385(6),c=0.9421(5) nm.α=91.69(4)°,β=98.49(4)°,γ=99.16(5)°,Z=2,V=1.436 nm^3.The structure was refined to R value of 0.0866.Each Nd atom is connected with other two Nd atoms by two bidentate and two tridentate carboxyl groups to form a linear polymer.The Nd atom is further coordinated by a chelating carboxyl and two ethanol molecules.So the central atom is nine-coordinated with a distorted monocapped square-antiprism geometry.The infrared spectra and the thermal analysis of the complexes were also studied.

Synthesis, Molecular Spectroscopy, Computational, Thermal Analysis and Biological Activity of Some Orotic Acid Complexes

Binary orotic acid metal complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), and two mixed metals complexes of (Co(II), Ni(II)) and (Ni(II), Cu(II)) were synthesized and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility, and ESR spectra. The Analysis proved that the ligand has different coordination modes and the complexes were of octahedral, tetrahedral, and trigonal bipyramidal geometries. Molecular modeling techniques and quantum chemical methods have been performed for orotic acid to calculate charges, bond lengths, bond angles, dihedral angles, electronegativity (χ), chemical potential (μ), global hardness (η), softness (σ) and the electrophilicity index (ω). The thermal decomposition of the complexes was monitored by TGA, DTA, and DSC techniques under the N2 atmosphere. The thermal decomposition mechanisms of the complexes were suggested. The biological activity of orotic acid and some of the complexes are tested against antibacterial and antifungal organisms.

PRELIMINARY STUDIES ON THE SYNTHESIS AND CHARACTERIZATION OF OXY-AND THIO-DIACETIC ACID HYDRAZITION AND THEIR FIRST-ROW TRANSITION METAL COMPLEXES

It has been made certain that thio-and oxy-diacetic acid hydrazides are potential anticancer compounds.However,their ability to form complexes with transition metals and the properties of the complexes thus formed have not been studied.Employing a new potential anticancer ligand 1,2-bis(thioacetic acid hydrazide)ethane prepared in our lab,along with ligands oxydiacetic hydrazide and 1,2-bis(oxyacetic acid hydrazide) ethane,a series of 11 new first-row transition metal(M=Zn^(2+),Cu^(2+),Co^(2+), Ni^(2+))complexes with each of the above three ligands have been synthesized and characterized by means of elemental analyses,IR,TG and X-ray powder diffraction.

Investigation on Molecular and Crystal Structures of Metal Complexes with Aminopolycarboxylic Acids(Ⅰ)─Synthesis and Structure of Na_2[Fe~Ⅲ(ida)2]2·3H_2O

The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data are as follows; Monoclinic, P21/c, a=15.6480(10)A,b=16.7870(10)A, c=10.347(2)A, β=90.790(10), V=2717.7(6)A3, Z=3, and R=0.0333 for 4789 unique reflections. The complex anion has a pseudo-octahedral structure distorted more than the CrⅢand CoⅢ analogs, in which cach iminodiacetato ligand (ida2-) is coordinated in a facial fashion with the two N atoms in a cis configuration, resulting in an unsyin-fac structure.

Synthesis,O_2-binding ability and catalytic oxidation performance of cobalt(Ⅱ) complexes with dihydroxamic acid functionalized N-pivot lariat ethers

Novel Co（Ⅱ） complexes with dihydroxamic acids functionalized N-pivot lariat ether CoL^1-CoL^4 were synthesized and characterized.Their oxygenation constants（ln K_（O2）） and thermodynamic parameters（△H°,△S°） were measured.And their catalytic performance in oxidation of p-xylene to p-toluic acid（PTA） was investigated.The enhancement of O_2-binding and catalytic oxidation activity by the oxa aza crown ether ring of the cobalt complexes were discussed.

SYNTHESIS OF CHIRAL MIXED-LICAND COMPLEXES AND THEIR USE IN ASYMMETRIC SYNTHESIS OF CHRYSANTHEMIC ACID

Several chiral mixed-ligand complexes have been synthesized and their efficiency as catalysts for the asymmetric synthesis of chrysanthemic acid tested.

Syntheses, Structures, and Luminescent Properties of the ZnⅡ and CdⅡ 1-D Chain Polymers Assembled by Salicylhydroxamic Acid

TWO complexes of compositions [Zn（H2shi）（CHsCOO）]. （1） and [Cd（H2shih（H20）]. （2） （H3shi = salicylhydroxamic acid） have been prepared under solvothermal conditions. They are characterized by X-ray single-crystal diffraction, IR and elemental analysis. The crystal of 1 belongs to the tetragonal system, space group I41/a with a = 18.972（3）, b = 18.972（3）, c = 10.938（2） A, V= 3937.1（I） A3, C9H9NOsZn, Mr - 276.54, Z = 16, Dc = 1.866 g/cm3,μ = 2.500 mm-1, F（000） = 2240, the final R = 0.0425 and wR = 0.123. The crystal of 2 belongs to the monoclinic system, space group P2/c with a = 16.647（3）, b = 6.4577（I）, c = 6.5623（I） A, V = 702.4（2） A3, C14H4Cd2N2OT, Mr = 434.68, Z = 2, Dc = 2.055 g/cm3,μ = 1.599 mm-1, F（000） = 432, the final R = 0.0211 and wR = 0.0761. They both possess I-D polymeric chain structures. The luminescent properties of complexes I and 2 have been investigated.

Solvothermal Syntheses, Crystal Structures, Thermal Stability and Quantum Chemistry of Dinuclear Trialkyltin Complexes Constructed by Camphoric Acid

Two dinuclear organotin complexes C8H14（CO2SnCy3）2（1）（Cy = cyclohexyl group） and C8H14[CO2Sn（CH2CMe2Ph）3]2（2） were synthesized by the reactions of camphoric acid with tricyclohexyltin hydroxide and bis[tri（2-methyl-2-phenyl）propyltin] oxide under solvothermal conditions, and these complexes were characterized by infrared spectra, elemental analyses, and H NMR spectra. The crystal of 1 belongs to the monoclinic system, space group P21/c with a = 1.83478（19）, b = 1.52707（18）, c = 1.9849（2） nm, β = 122.515（7）°, Z = 4, V = 4.6896（9） nm^3, Dc = 1.324 g/cm^3, μ（MoKα） = 1.103 mm^-1, F（000） = 1952, R = 0.0697 and wR = 0.2040. In addition, thermal stability and quantum chemical calculation of 1 were also studied.

Hydrothermal Synthesis, Crystal Structure and Fluorescent Property of a Cd(Ⅱ) Complex Based on Biimidazole and Isonicotinate-N-oxide

A new complex [Cd（H2biim）2（H2O）2]·（ino）2·4H2O （H2biim = 2,2＇-biimidazole, ino = isonicotinate-N-oxide） has been prepared and characterized by single-crystal X-ray diffraction analysis, IR and fluorescence spectra analysis. The crystal is of triclinic system, space group P1 with a = 7.5380（6）, b = 8.0402（7）, c = 13.5094（11） , α = 104.269（1）, β = 93.604（1）, γ = 98.349（1）°, V = 780.93（11） 3, Mr = 765.00, Dc = 1.627 g/cm3, F（000） = 390, μ = 0.776 mm-1 and Z = 1. The final R = 0.0322 and wR = 0.0825 for 7038 observed reflections with I 2σ（I） and R = 0.0341 and wR = 0.0832 for all data. The title complex exhibits an infinite chain-like structure through bridging isonicotinate-N-oxide. Strong interchain hydrogen bonds between isonicotinate-N-oxide and H2biim result in the robust 3-D supramolecular architecture. Moreover, the complex shows strong photoluminescence with emission maximum at λ = 401 nm upon λex = 330 nm.

Synthesis, Structure and Thermochromic Properties of a Copper(Ⅱ) Complex Based on Naphthyl Carboxylate and Benzimidazolyl Ligands

One novel copper（Ⅱ） complex, [Cu（NAA）2（bim）2]·H2O （1, HNAA = a-naphthylacetic acid, bim = benzimidazole） has been synthesized and characterized by X-ray single-crystal diffraction analysis, elemental analysis, and IR spectrum. It crystallizes in monoclinic, space group C2/c with a = 1.15969（12）, b = 1.9757（2）, c = 1.45763（16） nm, β = 104.712（2）°, V = 3.2298（6） nm3, Z = 4, C38H32N4O5Cu, Mr = 688.22, Dc = 1.418 g/cm-3, μ = 0.729 mm-1, S = 1.039, F（000） = 1428, the final R = 0.0380 and wR = 0.0912 for 2849 unique reflections. In 1, two carboxylate and two benzimidazole ligands coordinate to the central Cu（Ⅱ） atom by a bidentate chelate mode. Interesting, reversible thermochromic properties of 1 can be observed and investigated by thermal analysis method.