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 Cand...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.展开更多
A new unsymmetrical solid Schiff base (LLi) was synthesized using L-lysine, o-vanillin and 2-hydroxy-l-naphthaldehyde. Solid La(Ⅲ) complex of this ligand [LaL(NO3)](NO3)·2H2O was prepared and characterized by el...A new unsymmetrical solid Schiff base (LLi) was synthesized using L-lysine, o-vanillin and 2-hydroxy-l-naphthaldehyde. Solid La(Ⅲ) complex of this ligand [LaL(NO3)](NO3)·2H2O was prepared and characterized by elemental analyses, IR, UV and molar conductance. The thermal decomposition kinetics of the complex for the second stage were studied under non-isothermal condition by TG and DTG methods. The kinetic equation may be expressed as: dα/dt=A·e-E/RT·(1-α)2. The kinetic parameters(E, A), activation entropy S≠ and activation free-energy G≠ were also gained.展开更多
A new La（Ⅲ） complex, {[La（L）（NO3）（H2O）3]·H2O}n （L = 1,10-phenanthroline- 2,9-dicarboxylate）, has been synthesized and structurally determined by X-ray diffraction analysis. The complex crystallizes in ...A new La（Ⅲ） complex, {[La（L）（NO3）（H2O）3]·H2O}n （L = 1,10-phenanthroline- 2,9-dicarboxylate）, has been synthesized and structurally determined by X-ray diffraction analysis. The complex crystallizes in the monoclinic system, space group P21/c with a = 7.7358（17）, b = 8.1664（18）, c = 28.271（6） A, β= 95.184（4）°, V= 1778.6（7） A3, Z = 4, C14H14LaN3O11, Mr = 539.19, Dc = 2.014 g/cm^3, μ= 2.471 mm^-1, F（000） = 1056, the final R = 0.0350 and wR = 0.0659. In this complex, each metal center adopts a ten-coordination geometry formed by two N atoms from a ligand L and eight O atoms from three H2O molecules, a nitrate ion and carboxylates of two ligands. Each ligand adopts a N2,O3-pentdentate coordination mode using two N and two O atoms chelating a La（Ⅲ）, and using another O atom of carboxylate to bridge another La（Ⅲ） center resulting in a 1D helical chain molecule. Intermolecular strong O-H…O and weak C-H…O hydrogen bonds extend the 1D chain structure into a 3D supramolecular architecture.展开更多
A new complex La(ENX)_3Cl_3·2H_2O was synthesized. The interaction between La-Enoxacin complex and bovine serum albumins (BSA) were studied by fluorescence and UV-Vis absorption spectra. The research results indi...A new complex La(ENX)_3Cl_3·2H_2O was synthesized. The interaction between La-Enoxacin complex and bovine serum albumins (BSA) were studied by fluorescence and UV-Vis absorption spectra. The research results indicate that the combination reaction of them is a single static quenching process, La-Enoxacin complex strongly bound BSA, the equilibrium constant K_0=1.45×107 L·mol -1 (at 25 ℃). The shortest binding distance(r) and energy transfer efficiencies(E) between donor (BSA) and acceptor (La-Enoxacin) obtained by Frster′s nonradiative energy transfer mechanism are as follows, r=4.07 nm, E=0.118. The hydrophobic force plays major role in the reaction.展开更多
A new stripping agent N,N-dimethyl-3-oxa-glutaramic Acid (DOGA) was used in TRPO process to simplify the TRPO process. The structures of the complexes of the DOGA with Eu(Ⅲ), Nd(Ⅲ), La(Ⅲ) were characterized with ex...A new stripping agent N,N-dimethyl-3-oxa-glutaramic Acid (DOGA) was used in TRPO process to simplify the TRPO process. The structures of the complexes of the DOGA with Eu(Ⅲ), Nd(Ⅲ), La(Ⅲ) were characterized with extended X-ray absorption fine structure spectroscopy (EXAFS), infrared spectra (IR) and mass spectra (MS). The molecular formula of the complexes of Eu(Ⅲ) and Nd(Ⅲ) is deduced to be M(DOGA)_3, and only La(Ⅲ) can form the complex HM(DOGA)_4 under condition of high consistency of the DOGA. The coordination number of Ln(Ⅲ) in the complexes is 8, and all of coordinated donor atoms are O atoms. For Eu(Ⅲ), Nd(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of Ln-O are 0 240 nm, 0 244 nm respectively, while the numbers of the second O shell are 2.4, and the average coordination bond lengths of Ln-O are 0 260 nm, 0 262 nm. For La(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of La-O are 0 258 nm, while the number of O atom in the second coordination shell is 4.4, and the average coordination bond length of La-O is 0 28 nm. The results of IR and MS show that there is no water coordinating with Ln(Ⅲ) in the complexes.展开更多
Lanthanum and nitrogen co-doped SrTiO3 was synthesized using polymerized complex method with Ti(OC3H7)4, SrCl2·6H2O and La(NO3)3·6H2O as starting materials followed by calcinations in NH3. Ethylene glycol an...Lanthanum and nitrogen co-doped SrTiO3 was synthesized using polymerized complex method with Ti(OC3H7)4, SrCl2·6H2O and La(NO3)3·6H2O as starting materials followed by calcinations in NH3. Ethylene glycol and anhydrous citric acid were used as the precursors of synthesis. The samples were characterized using XRD, TEM, DRS, BET, EDX and XPS. The cubic-perovskite type of La/N co-doped SrTiO3 nanoparticle could be successfully synthesized. The photocatalytic activity of SrTiO3 for DeNOx ability in visible light region (λ > 510 nm) could be improved by co-doping of La3+ and N3_. The high visible light photocatalytic activity of this substance was caused by a narrow band gap energy that enables to absorb visible light.展开更多
La-Mo series complex oxide ultrafine particles have been prepared successfully by the sol-gel method at low tomperature. The infiuence of preparation conditions and thermal treatment conditions on the morphology and t...La-Mo series complex oxide ultrafine particles have been prepared successfully by the sol-gel method at low tomperature. The infiuence of preparation conditions and thermal treatment conditions on the morphology and the structure of the oxide particles has been studied by using XRD, DTA-TG, TEM, FT-IR and BET surface area measurement methods. For the preparation of the well-distributed La-Mo series complex oxide ultrafine particles with the size in the range of 40-80nm, the optimum conditions are:ncitrie/nLa+Mo=0.3, pH≤1.5, t≤500℃.展开更多
文摘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.
文摘A new unsymmetrical solid Schiff base (LLi) was synthesized using L-lysine, o-vanillin and 2-hydroxy-l-naphthaldehyde. Solid La(Ⅲ) complex of this ligand [LaL(NO3)](NO3)·2H2O was prepared and characterized by elemental analyses, IR, UV and molar conductance. The thermal decomposition kinetics of the complex for the second stage were studied under non-isothermal condition by TG and DTG methods. The kinetic equation may be expressed as: dα/dt=A·e-E/RT·(1-α)2. The kinetic parameters(E, A), activation entropy S≠ and activation free-energy G≠ were also gained.
基金Supported by the Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality
文摘A new La（Ⅲ） complex, {[La（L）（NO3）（H2O）3]·H2O}n （L = 1,10-phenanthroline- 2,9-dicarboxylate）, has been synthesized and structurally determined by X-ray diffraction analysis. The complex crystallizes in the monoclinic system, space group P21/c with a = 7.7358（17）, b = 8.1664（18）, c = 28.271（6） A, β= 95.184（4）°, V= 1778.6（7） A3, Z = 4, C14H14LaN3O11, Mr = 539.19, Dc = 2.014 g/cm^3, μ= 2.471 mm^-1, F（000） = 1056, the final R = 0.0350 and wR = 0.0659. In this complex, each metal center adopts a ten-coordination geometry formed by two N atoms from a ligand L and eight O atoms from three H2O molecules, a nitrate ion and carboxylates of two ligands. Each ligand adopts a N2,O3-pentdentate coordination mode using two N and two O atoms chelating a La（Ⅲ）, and using another O atom of carboxylate to bridge another La（Ⅲ） center resulting in a 1D helical chain molecule. Intermolecular strong O-H…O and weak C-H…O hydrogen bonds extend the 1D chain structure into a 3D supramolecular architecture.
文摘A new complex La(ENX)_3Cl_3·2H_2O was synthesized. The interaction between La-Enoxacin complex and bovine serum albumins (BSA) were studied by fluorescence and UV-Vis absorption spectra. The research results indicate that the combination reaction of them is a single static quenching process, La-Enoxacin complex strongly bound BSA, the equilibrium constant K_0=1.45×107 L·mol -1 (at 25 ℃). The shortest binding distance(r) and energy transfer efficiencies(E) between donor (BSA) and acceptor (La-Enoxacin) obtained by Frster′s nonradiative energy transfer mechanism are as follows, r=4.07 nm, E=0.118. The hydrophobic force plays major role in the reaction.
基金Project supported by the China National"863"Program
文摘A new stripping agent N,N-dimethyl-3-oxa-glutaramic Acid (DOGA) was used in TRPO process to simplify the TRPO process. The structures of the complexes of the DOGA with Eu(Ⅲ), Nd(Ⅲ), La(Ⅲ) were characterized with extended X-ray absorption fine structure spectroscopy (EXAFS), infrared spectra (IR) and mass spectra (MS). The molecular formula of the complexes of Eu(Ⅲ) and Nd(Ⅲ) is deduced to be M(DOGA)_3, and only La(Ⅲ) can form the complex HM(DOGA)_4 under condition of high consistency of the DOGA. The coordination number of Ln(Ⅲ) in the complexes is 8, and all of coordinated donor atoms are O atoms. For Eu(Ⅲ), Nd(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of Ln-O are 0 240 nm, 0 244 nm respectively, while the numbers of the second O shell are 2.4, and the average coordination bond lengths of Ln-O are 0 260 nm, 0 262 nm. For La(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of La-O are 0 258 nm, while the number of O atom in the second coordination shell is 4.4, and the average coordination bond length of La-O is 0 28 nm. The results of IR and MS show that there is no water coordinating with Ln(Ⅲ) in the complexes.
文摘Lanthanum and nitrogen co-doped SrTiO3 was synthesized using polymerized complex method with Ti(OC3H7)4, SrCl2·6H2O and La(NO3)3·6H2O as starting materials followed by calcinations in NH3. Ethylene glycol and anhydrous citric acid were used as the precursors of synthesis. The samples were characterized using XRD, TEM, DRS, BET, EDX and XPS. The cubic-perovskite type of La/N co-doped SrTiO3 nanoparticle could be successfully synthesized. The photocatalytic activity of SrTiO3 for DeNOx ability in visible light region (λ > 510 nm) could be improved by co-doping of La3+ and N3_. The high visible light photocatalytic activity of this substance was caused by a narrow band gap energy that enables to absorb visible light.
文摘La-Mo series complex oxide ultrafine particles have been prepared successfully by the sol-gel method at low tomperature. The infiuence of preparation conditions and thermal treatment conditions on the morphology and the structure of the oxide particles has been studied by using XRD, DTA-TG, TEM, FT-IR and BET surface area measurement methods. For the preparation of the well-distributed La-Mo series complex oxide ultrafine particles with the size in the range of 40-80nm, the optimum conditions are:ncitrie/nLa+Mo=0.3, pH≤1.5, t≤500℃.
