Synthesis,spectral characterization,thermal and biological studies of lanthanide(Ⅲ) complexes of oxyphenbutazone

Lanthanide(III) complexes of 4-butyl-1-(4-hydroxyphenyl)-2-phenyl-3,5-pyrazolidinedione(OPB) were prepared by homogeneous precipitation. The solid complexes were characterized by elemental analysis, magnetic susceptibility data, molar conductivity measurements and IR, UV-Vis, mass,1H NMR and13C NMR spectral methods. The thermal decomposition of the complexes under static air atmosphere was investigated by simultaneous TG/DTG at a heating rate of 10 °C/min. The final decomposition products were found to be metal oxides. The spectroscopic data suggested that OPB acted as a bidentate, mono-ionic ligand coordinating through two carbonyl oxygens of the pyrazolidinedione ring. The kinetic and thermodynamic parameters such as activation energy, pre-exponential factor and entropy of activation for each step of the decomposition reactions were evaluated using Coats-Redfern and MacCallum-Tanner equations. The negative entropy values of the complexes indicated that the activated complexes had a more ordered structure than the reactant and that the reactions were slower than normal. Investigations of antimicrobial activity of the compounds were carried out by the disk diffusion technique.     

Synthesis,spectroscopic characterization,DNA cleavage and antibacterial studies of a novel tridentate Schiff base and some lanthanide（III） complexes

A novel potential tridentate Schiff base was prepared by condensing equimolar quantities of 2-hydroxyacetophenone and 2-aminopyrimidine in methanol. This ligand was versatile in forming a series of complexes with lanthanide ions such as La（III）, Pr（III）, Nd（III）, Sm（III）, Gd（III）, Dy（III） and Yb（III）. The ligand and the metal complexes were characterized through elemental analysis, molar conductance, UV-Visible, IR, 1H NMR, and mass spectral studies. The spectral studies indicated that the ligand was coordinated to the metal ion in neutral tridentate fashion through the azomethine nitrogen, one of the nitrogen atoms in the pyrimidine ring and the phenolic oxygen without deprotonation. Thermal decomposition and luminescence property of lanthanum（III） complex were also examined. The X-ray diffraction patterns showed the crystalline nature of the ligand and its lanthanum（III） complex. The DNA cleavage studies of the ligand and the metal complexes were carried out and it was observed that the lanthanum（III） and neo-dymium（III） complexes cleaved the pUC19 DNA effectively. The ligand and the metal complexes were screened for their antibacte-rial activities. The metal complexes were found to be more potent bactericides than the ligand.     

Synthesis,characterization, thermal behavior,and antifungal activity of La（III） complexes with cinnamates and 4-methoxyphenylacetate

In this study a series of trivalent lanthanum complexes with 4-（R）-cinnamate （4-Rcinn, R=H（1）, MeO（2）, Cl（3）） and 4-methoxyphenylacetate ligands （4） were prepared and their antifungal activity against Candida albicans, Aspergillus niger and Trichophyton mentagrophytes were examined. Compounds 1-4 were synthesized by a metathesis reaction and fully characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy, fluorescence spectra, thermogravimetry （TG）, derivative thermogravimetry （DTG）, differential scanning calorimetry （DSC） and X-ray diffraction powder patterns. In emission studies, it was observed that lu-minescence intensity was enhanced in the presence of lanthanide ion. The results of X-ray diffraction patterns indicated that all com-plexes studied exhibited crystalline structure. Thermal behavior by TG, DTG, and DSC studies permitted to estimating the hydration degree of the compounds and showed the formation of decomposition products like lanthanum oxide. Determined by antifungal stud-ies, lanthanum complexes 1-4 demonstrated antifungal activity toward all pathogenic fungal strains tested. Compounds 2 and 4 showed significant growth inhibition for A. niger and C. albicans, respectively.     

Synthesis, fluorescence properties of Eu（III） complexes with novel carbazole functionalized β-diketone ligand

A novel carbazole functionalized β-diketone, methyl 6-(9-ethylcarbazole-3-yl)-oxoacetyl-2-pyridinecarboxylate (MEP), and its corresponding binary Eu(III) complexes Eu(MEP)₃·2H₂O and ternary complex Eu(MEP)₃Phen with 1,10-Phenanthroline (Phen) were prepared. The ligand was characterized based on elemental analysis, FT-IR, and ¹H NMR, and the complexes were characterized with elemental analysis, FT-IR and thermogravimetric and differential thermal analysis (TG-DTA). The investigation of fluorescence properties of the complexes Eu(MEP)₃·2H₂O and Eu(MEP)₃Phen showed that the Eu(III) ion could be sensitized efficiently by the ligand to some extent, in particular, in the ternary system, the secondary ligand Phen acting as a light-harvesting center was involved in the highly efficient energy transfer process, and the emission was stronger than the binary complex. In addition, the introduction of the carbazole moiety enlarged the π-conjugated system of the ligand and enhanced the luminescent intensity of the complexes.     

Synthesis, Characterization and Fluorescence of Phenylcarboxymethyl Sulfoxide Complexes with Lanthanide Nitrates

Ｒａｒｅｅａｒｔｈｃｏｍｐｌｅｘｅｓｗｉｔｈｓｕｌｆｏｘｉｄｅａｎｄａｒｏｍａｔｉｃｃａｒｂｏｘｙｌａｃｉｄｈａｖｅｂｅｅｎｗｉｄｅｌｙｓｔｕｄ ｉｅｄ[1～ 3 ] .Ｉｔｉｓｐｒｏｖｅｄｔｈａｔｔｈｅｙｂｏｔｈｈａｖｅｂｅｔ ｔｅｒｆｌｕｏｒｅｓｃｅｎｃｅｃｈａｒａｃｔｅｒ .Ｈｏｗｅｖｅｒｔｈｅａｒｏ ｍａｔｉｃｃａｒｂｏｘｙｌｏｆｒａｒｅｅａｒｔｈｃｏｍｐｌｅｘｅｓｈａｖｅｖｅｒｙｈｉｇｈｆｌｕｏｒｅｓｃｅｎｃｅｅｍｉｓｓｉｏｎｉｎｔｅｎｓｉｔｙａｎｄｓｔａｂｉｌｉｔｙ ,ｂｕｔｓｏｌｕｂｉｌｉｔｙｉ…     

Interaction of TbCl3 and lanthanide complexes with poly（N-vinylpyrrolidone）

The interaction of TbCl3 and lanthanide(III) β-diketonate complexes with poly(N-vinylpyrrolidone)(PVP) polymer was studied using fluorescence spectroscopy. In the presence of PVP the emission of Tb3+ in ethanolic solution of TbCl3 significantly increased owing to the excitation energy transfer from PVP to Tb3+ ions, which was more efficient as compared to a direct excitation of the Tb3+ 4f75d1 levels. In contrast, emission of NEt4Tb(hfa)4 and NEt4Eu(hfa)4 complexes was almost completely quenched in solution containing PVP. The PVP bound both Ln3+ ions and hfa ligands which caused decomposition of Ln-hfa complexes and switched off the excitation energy transfer from the ligand to the emitting Ln3+ ion. The important role of hydrogen bonds in stabilization of interaction of hfa ligands with PVP was indicated.     

Synthesis, Characterization and Crystal Structure of Neutral Homoleptic Lanthanide Amide Yb（NPh2）3（THF）2

A neutral homoleptic lanthanide amide Yb(NPh2)3(THF)2 was obtained by reaction of anhydrous YbCl3 with LiNPh2 in THF. The product was characterized by elemental analysis, infrared spectrum and X-ray crystallographic analysis. The crystal data are monoclinic, P21/n space group, a=1.2052(2) nm, b=1.9369(3) nm, c=1.6523(2) nm, β=92.79(1)°, V=3.8524(9) nm3, Z=4, Dc=1.417 g*cm-3, μ=24.67 cm-1 (Mo Kα), F(000)=1668, R=0.036, Rw=0.039. The central metal ytterbium is coordinated by three terminal NPh2 groups and two THF molecules to form a five-coordinate distorted trigonal bipyramid. The mean Yb-N bond length is 0.2219(6) nm.     

Synthesis, spectroscopic characterization and thermal studies of some lanthanide(Ⅲ) nitrate complexes with a hydrazo derivative of 4-aminoantipyrine

A heterocyclic ligand synthesized by the coupling of diazotized 4-aminoantipyrine with acetylacetone reacted with lanthanide(III) nitrate to form complexes of the type [Ln(HAAP)₂(NO₃)₃] where, Ln=La(III), Ce(III), Pr(III), Nd(III), Sm(III), or Gd(III) and HAAP= 3-{[2-(N-1-phenyl-2,3-dimethylpyrazol-3-in-5-on-4-yl)]hydrazone}pent-2,3,4-trione. The ligand and 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 spectral data revealed that the ligand existed in the hydrazo form and coordinated to the metal ion without deprotonation in a neutral tridentate manner, through carbonyl oxygen of pyrazolone ring, hydrazo nitrogen and carbonyl oxygen of the acetylacetone moiety. The molar conductance values adequately supported their non-electrolytic nature. The ligand and the praseodymium(III) complex were subjected to X-ray diffraction studies. Thermal decomposition behavior of the lanthanum(III) complex was also examined.     

Syntheses and fluorescent properties of complexes of Eu（III） with HTTA, TPPO and benzoic acid

A series of Eu(III) complexes of α-thenoyltrifluoroacetone(HTTA) with trioctylphosphine oxide(TPPO) and benzoic acid(BA) or its two derivatives, p-toluic acid(PTA) and p-methoxybenzoic acid(POA) were synthesized and were characterized with elemental analysis, IR spectroscopy, scanning electronic microscopy and fluorescent spectra. The complexes were revealed to be Eu(BA)(TTA)₂TPPO₂, Eu(PTA)(TTA)₂TPPO₂ and Eu(POA)(TTA)₂TPPO₂. The excitation and absorption spectra of the complex Eu(POA)(TTA)₂TPPO₂ in MeOH solution were investigated in detail. The experimental result showed that relatively cheap materials with sharp red luminescence could be prepared, when benzoic acid or its two derivatives were added in Eu(III) complexes of α-thenoyltrifluoroacetone with trioctylphosphine oxide. The relative fluorescence intensity of the Eu(III) complexes decreased in the following order: Eu(POA)(TTA)₂TPPO₂> Eu(PTA)(TTA)₂TPPO₂>Eu(BA)(TTA)₂TPPO₂.     

Synthesis, crystal structure and characterization of one-dimension complex constructed by terbium（III） and 2-iodobenzoate

The complex of [Tb(2-IBA)₃(H₂O)₂]_n (2-IBA=2-iodobenzoate)was prepared by solvent method from TbCl₃·6H₂O and 2-iodobenzoic acid. The crystal structure was determined with X-ray single-crystal diffraction. The X-ray diffraction analysis indicated that the title complex crystallized in triclinic crystal system and Pī space group. The Tb³⁺ ion was coordinated by six oxygen atoms from five 2-IBA ligands and two oxygen atoms from two water molecules, giving a distorted square-antiprism polyhedral geometry. The carboxyl groups were bonded to the Tb³⁺ ions with bidentate-bridging and bidentate-chelating coordination modes. The adjacent Tb³⁺ ions were linked by two bidentate-bridging 2-IBA ligands, forming 1-D chain structure. The fluorescence spectrum of the complex showed four main peaks at 489, 543, 587, and 618 nm, corresponding to ⁵D₄→⁷F_J (J=6?3) transition emissions of the Tb³⁺ ion, respectively.     

Synthesis and spectral characterization of lanthanide complexes with 1,2-diphenyl-4-butyl-3,5-pyrazolidinedione： Luminescent property of Tb（Ⅲ） complex

The complexes of rare earth elements with 1,2-diphenyl-4-butyl-3,5-Pyrazolidinedione (PBH, phenylbutazone) were synthesized and characterized by elemental analysis, molar conductance, IR, UV-Vis, EPR and magnetic moment measurements. Based on these studies the complexes were formulated as [Ln(PB)3(H2O)2]?nH2O, where Ln=Eu(III), Gd(III), Tb(III), Dy(III) and Er(III). From IR spectra, it was found that PBH acted as a bidentate mono-ionic ligand coordinating through two carbonyl oxygen of the pyrazolidinedione ring. The thermal analysis of all the complexes was carried out at a heating rate of 10 oC/min. The kinetic aspects of the complexes were evaluated. The nega-tive entropy value of the complexes indicated a more ordered state for the activated complexes. The photoluminescence property of Tb(III) complex was investigated. It showed all the characteristic emission peaks of Tb3+ with a life time of 0.98914 ms.     

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.     

Synthesis and Characterization of Tetravalent Cerium Complexes with p-Tert-butylcalix[ n ] arenes （ n = 4, 6, 8）

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Synthesis,spectroscopic characterization,and thermal decomposition kinetics of some lanthanide（Ⅲ） nitrate complexes of 2-（N-o-hydroxyacetophenone） amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene

Complexes of La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Dy（Ⅲ）, Yb（Ⅲ）, and Lu0ID with 2-（N-o- hydroxyacetophenone）amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene （HAAT） formed by the condensation of o-hydroxyacetophenone and 2-amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene were synthesized and characterized on the basis of elemental analyses, molar conductance measurements, magnetic susceptibility data, UV-Visible, IR, and NMR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate coordinating to the metal ion through ONO donor sequence. A coordination number nine was proposed for the complexes. Thermal decomposition studies of the ligand and lanthanum（Ⅲ） complex were carried out and kinetic parameters were calculated using Coats-Redfem equation. The decomposition reactions followed random nucleation mechanism with one nucleus on each particle.     

Synthesis, characterization, fluorescence and DNA-binding studies of europium（Ⅲ） pirates complexes with amide-based 2,3-dihydroxynaphthalene derivatives

Two ligands 2,2′-[2,3-naphthylenebis(oxy)]-bis(N-benzyl(acetamide))(L1) and 2,2′-[2,3-naphthylenebis (oxy)]-bis(N,N-diphenyl (acetamide))(L2) and their europium(Ⅲ) picrate complexes were synthesized. The complexes were characterized by elemental analysis, infra-red (IR), thermogravimetry and differential thermal analysis (TG-DTA) and molar conductivity. Fluorescent experiments showed that the resonance level of the Eu) matched better to the triplet state energy level of the ligand L2 than that of the ligand L1 and the fluorescence in-tensities of the complexes were reduced with the raising coordination ability of solvent. In addition, the interactions between the complexes and DNA were studied by means of spectrometry and cyclic voltammetry. The results suggested that the complexes could bind to DNA through intercalation and the complex 1 binded to DNA more strongly than the complex 2.     

Synthesis, Characterization and Antitumor Activity of Lanthanum （Ⅲ） Complex with Demethylcantharidate

Becausetherareearthelementshashigheraffini tytotumortissuethantonormaltissue,theradioac tiverareearthelementswereusedtodiagnoseand treatthemalignanttumorsintheearlieryears.Howev erthetherapeuticeffectwiththoseelementsisnot good.Recently,moreresearchesfocu…     

Synthesis and Structural Characterization of Erbium Complex with Tripodal Ligand, N, N, N＇, N＇ N＂ N＂-Hexaisopropyl-2,2＇, 2＂-Nitrilotris （2,1-ethoxy） triacetamide （L）

A new tripodal ligand, N, N, N‘, N‘, N“, N“-hexaisopropyl-2, 2‘, 2“-nitrilotris (2, 1-ethoxy)-triacetamide (L) and its new erbium picrate complex were prepared. The structure of the complex was determined by Xray crystal structure analysis. The result reveals that the Er^3 is encapsulated by the three arms of the tripodal ligand, and nine-coordinated by the bridged-head nitrogen atom, all ether oxygen atoms and carbonyl oxygen atoms of the ligand, and two oxygen atoms of the bidentate picrate. The coordination polyhedron is a distorted monocapped square antiprism.     

Synthesis, characterization and thermostability of tris（2,2,6,6-tetramethyl-3,5- heptanedionato）yttrium（III）

The metal-organic chemical vapor deposition (MOCVD) technique is a promising process for high temperature superconductor YBa2Cu3O7-δ(YBCO) preparation. In this technique, the purity, evaporation characteristics and thermostability of adopted precursors will decide the quality and reproducible results of YBCO film. In the present report, tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III)(Y(TMHD)3) was synthesized by the interaction of yttrium nitrate hydrate with TMHD in methanol solution, and its structure was identified by FTIR, 1 H NMR, 13C NMR and EI-MS spectroscopy. Subsequently, the thermal property and the kinetics of decomposition were systematically investigated by non-isothermal thermogravimetric analysis methods (TGA) at different heating rates in streams of N2,and the average apparent activation energy of evaporation process was evaluated by the Ozawa, Kissinger and Friedman methods. The possible conversion function was estimated through the Coats-Redfern method to characterize the evaporation patterns and followed a phase boundary reaction mechanism by the contracting area equation with average activation energy of 88.9kJ/mol.     

Synthesis, Characterization and Luminescence Properties of Rare Earth Complexes with Bis （Pyridinyl-Amide）

A ligand, N^1, N^4-di （ pyridin-2-yl ） succi- namide （L） and its lanthanide（ IH ） complexes （RE = La, Eu, Tb, Gd, Yb ） were synthesized and characterized in detail. The results indicate that the composition of the binary complexes is determined as [ REL （H2O）2（NO3）2] NO3, that the complexes are 1 ： 1 electrolytes in DMF, and that the Tb^3＋ complex has brightly green fluorescence in a solid state. At the same time, the energy levels of the excited triplet states for the six ligands were determined to be 22989 -1 cm . The fact that the ligand sensitize Tb^3＋ complexes was explained by the relative energy gap between the lowest triplet energy level of the ligand （T） and ^5Dj of Tb^3＋ or Eu^3＋ . When 2000 cm^-1 〈 △E（T-^5D4） 〈 3000 cm^-1, the luminescent intensity of the Tb^3＋ complex is stronger. When 3000 cm^-1〈 △E （T-^5D1）, the luminescent intensity of the Eu^3＋ complex is weak- er or close to nil. This means that the triplet energy level of the ligand is a chief factor that dominates RE^3＋ luminescence.