The thermal decomposition reaction of Eu-2(p-MBA)(6)(PHEN)(2) (p-MBA=CH3C6H4COO, methylbenzoate; PHEN=C12H8N2, 1,10-phenanthroline) was studied in a static atmosphere using TG-DTG method. The thermal decomposition pro...The thermal decomposition reaction of Eu-2(p-MBA)(6)(PHEN)(2) (p-MBA=CH3C6H4COO, methylbenzoate; PHEN=C12H8N2, 1,10-phenanthroline) was studied in a static atmosphere using TG-DTG method. The thermal decomposition process of the complex was determined and its kinetics was investigated. Kinetic parameters were obtained from the analysis of TG-DTG curves by means of the Achar method and the Madhusudanan-Krishnan-Ninan (MKN) method. The most probable mechanism functions of the thermal decomposition reaction for the first stage are: f(alpha) =(1-alpha)(2), g(alpha) = (1-alpha)(-1)-1. The activation energy for the first stage is 255.18 kJ/mol, the entropy of activation DeltaS is 227.32 J/mol and the Gibbs free energy of activation DeltaG is 128.04 W/mol.展开更多
The europium heptadentate coordinatively unsaturated (Eu(III)) and the terbium (Tb(III)) 1,4,7,10-tetraazacyclododecane (cyclen) complexes 1 and 2 were used in conjunction with ligand 3 (1,3,5-benzene-trisethynylbenzo...The europium heptadentate coordinatively unsaturated (Eu(III)) and the terbium (Tb(III)) 1,4,7,10-tetraazacyclododecane (cyclen) complexes 1 and 2 were used in conjunction with ligand 3 (1,3,5-benzene-trisethynylbenzoate) to form the supramolecular self-assembly structures 4 and 5;this being investigated in both the solid and the solution state. The resulting self-assemblies gave rise to metal centered emission (both in the solid and solution) upon excitation of 3, confirming its role as a sensitizing antenna. Drop-cased examples of ligand 3, and the solid forms of 4 and 5, formed from both organic and mixture of organic-aqueous solutions, were analyzed using Scanning Electron Microscopy, which showed significant changes in morphology;the ligand giving rise to one dimensional structures, while both 4 and 5 formed amorphous materials that were highly dense solid networks containing nanoporous features. The surface area (216 and 119 m2·g^-1 for 4 and 5 respectively) and the ability of these porous materials to capture and store gases such as N2 investigated at 77 K. The self-assembly formation was also investigated in diluted solution by monitoring the various photophysical properties of 3–5. This demonstrated that the most stable structures were that consisting of a single antennae 3 and three complexes of 1 or 2 (e.g., 4 and 5) in solution. By monitoring the excited state lifetimes of the Eu(III) and Tb(III) ions in H2O and D2O respectively, we showed that their hydration states (the q-value) changed from -2 to 0, upon formation of the assemblies, indicating that the three benzoates of 3 coordinated directly to the each of the three lanthanide centers. Finally we demonstrate that this hierarchically porous materials can be used for the sensing of organic solvents as the emission is highly depended on the solvent environment;the lanthanide emission being quenched in the presence of acetonitrile and THF, but greatly enhanced in the presence of methanol.展开更多
Three Eu（III） ternary complexes, Eu（hfa-H）3（Phen）, Eu（hfa-H）3（Bipy） and Eu（hfa-H）3（Bath） （hfa = hexafluoroacetylacetonate, Phen = 1,10-phenanthroline, Bipy = 2,2＇-bipyridine, Bath = bathophenanthroline...Three Eu（III） ternary complexes, Eu（hfa-H）3（Phen）, Eu（hfa-H）3（Bipy） and Eu（hfa-H）3（Bath） （hfa = hexafluoroacetylacetonate, Phen = 1,10-phenanthroline, Bipy = 2,2＇-bipyridine, Bath = bathophenanthroline）, were synthesized. Their luminescent properties were studied by incorporating deuterated Eu（III） complexes in a poly（methylmethacrylate） （PMMA） matrix, and the results indicated that luminescent PMMA including Eu（hfa-D）3（Bath） showed promising results for applications to novel organic Eu（III） devices, such as the high-power laser materials. Additionally, all the three Eu（III） complexes exhibited good thermostabilization.展开更多
Two novel luminescent Eu（III） complexes with the formulas（NIP）Eu（DBM）3 1 and（ENIP）Eu（DBM）3 2(NIP=2-（naphtha-len-1-yl）-1H-imidazo [4,5-f] [1,10] phenanthroline,ENIP=1-ethyl-2-（naphthalen-1-yl）-1H-imidazo ...Two novel luminescent Eu（III） complexes with the formulas（NIP）Eu（DBM）3 1 and（ENIP）Eu（DBM）3 2(NIP=2-（naphtha-len-1-yl）-1H-imidazo [4,5-f] [1,10] phenanthroline,ENIP=1-ethyl-2-（naphthalen-1-yl）-1H-imidazo [4,5-f] [1,10] phenanthroline,DBM= dibenzoylmethanato) were successfully synthesized and characterized by IR and elemental analysis.The UV-vis absorption spectra and pho-toluminescence properties of the complexes were investigated,and the irradiation at the absorption band between 300-400 nm of europium complexes either in solution or in the solid state led to the emission of a sharp red band at;10 nm,a characteristic Eu3+ emission due to the transition of 5D0→7F2.Furthermore,the weak emission bands around 587 and 595 nm attributed to 5D0→7F0 and 5D0→7F1 transition were also displayed in the emission spectra.These results demonstrated that the Eu（III） ion was sensitized efficiently by the ligand and displayed photoluminescence with high intensity,narrow half-peak width,and monochromic light.The excited-state lifetimes of 1 and 2 were in the microsecond time scale,but the photoluminescence quantum yield of 2（0.03） was two times higher than that of 1（0.01） which should be at-tributed to the effect of the ethyl substituting in ENIP.展开更多
以2-噻吩乙醛酸(HL)为第一配体,红菲绕啉(Bath)为第二配体合成了一种新型Eu(Ⅲ)三元配合物.采用等离子体原子发射光谱(ICP)、元素分析、FT-IR和1 H NMR表征了配合物的组成及结构.通过热重(TG)和发光光谱研究了配合物的热稳定性与发光性...以2-噻吩乙醛酸(HL)为第一配体,红菲绕啉(Bath)为第二配体合成了一种新型Eu(Ⅲ)三元配合物.采用等离子体原子发射光谱(ICP)、元素分析、FT-IR和1 H NMR表征了配合物的组成及结构.通过热重(TG)和发光光谱研究了配合物的热稳定性与发光性能.结果表明,该配合物分子式为EuL3Bath·2H2O,具有良好的热稳定性.在最佳激发波长(270nm)的紫外光照射下,该配合物能发出Eu(Ⅲ)离子很强的特征红光,其中电偶极跃迁(5 D0→7F2,613nm)发射最强;此外,该配合物还表现出相对较长的衰减寿命(τ=1.17ms).展开更多
Eu(III) adsorption on rutile was investigated as a function of contact time,pH,ionic strength and Eu(III) concentration by using a batch experimental method.The effects of carbonate,sulfate,and phosphate were also stu...Eu(III) adsorption on rutile was investigated as a function of contact time,pH,ionic strength and Eu(III) concentration by using a batch experimental method.The effects of carbonate,sulfate,and phosphate were also studied.It was found that the kinetics of Eu(III) adsorption on rutile could be described by a pseudo-second-order model.The adsorption of Eu(III) on rutile is strongly pH-dependent,but relatively insensitive to ionic strength.A double layer model (DLM) with two inner-sphere Eu(III) surface complexes was applied to quantitatively interpret the adsorption of Eu(III) on rutile.There were no apparent effects of carbonate and sulfate on Eu(III) adsorption,whereas the presence of phosphate promoted Eu(III) adsorption on rutile.The surface complexes of Eu(III) on rutile were evidenced by X-ray photoelectron spectroscopy (XPS).展开更多
基金This project was financially supported by the Education Department of Hebei Province.]
文摘The thermal decomposition reaction of Eu-2(p-MBA)(6)(PHEN)(2) (p-MBA=CH3C6H4COO, methylbenzoate; PHEN=C12H8N2, 1,10-phenanthroline) was studied in a static atmosphere using TG-DTG method. The thermal decomposition process of the complex was determined and its kinetics was investigated. Kinetic parameters were obtained from the analysis of TG-DTG curves by means of the Achar method and the Madhusudanan-Krishnan-Ninan (MKN) method. The most probable mechanism functions of the thermal decomposition reaction for the first stage are: f(alpha) =(1-alpha)(2), g(alpha) = (1-alpha)(-1)-1. The activation energy for the first stage is 255.18 kJ/mol, the entropy of activation DeltaS is 227.32 J/mol and the Gibbs free energy of activation DeltaG is 128.04 W/mol.
基金Science Foundation Ireland (PI awards 13/IA/1865 to T.G. and 13/IA/1896 to W.S.)the Irish Research Council (Postgraduate Scholarship to DC)+1 种基金the European Research Council (CoG 2014 - 647719 to W.S.)the School of Chemistry, Trinity College Dublin.
文摘The europium heptadentate coordinatively unsaturated (Eu(III)) and the terbium (Tb(III)) 1,4,7,10-tetraazacyclododecane (cyclen) complexes 1 and 2 were used in conjunction with ligand 3 (1,3,5-benzene-trisethynylbenzoate) to form the supramolecular self-assembly structures 4 and 5;this being investigated in both the solid and the solution state. The resulting self-assemblies gave rise to metal centered emission (both in the solid and solution) upon excitation of 3, confirming its role as a sensitizing antenna. Drop-cased examples of ligand 3, and the solid forms of 4 and 5, formed from both organic and mixture of organic-aqueous solutions, were analyzed using Scanning Electron Microscopy, which showed significant changes in morphology;the ligand giving rise to one dimensional structures, while both 4 and 5 formed amorphous materials that were highly dense solid networks containing nanoporous features. The surface area (216 and 119 m2·g^-1 for 4 and 5 respectively) and the ability of these porous materials to capture and store gases such as N2 investigated at 77 K. The self-assembly formation was also investigated in diluted solution by monitoring the various photophysical properties of 3–5. This demonstrated that the most stable structures were that consisting of a single antennae 3 and three complexes of 1 or 2 (e.g., 4 and 5) in solution. By monitoring the excited state lifetimes of the Eu(III) and Tb(III) ions in H2O and D2O respectively, we showed that their hydration states (the q-value) changed from -2 to 0, upon formation of the assemblies, indicating that the three benzoates of 3 coordinated directly to the each of the three lanthanide centers. Finally we demonstrate that this hierarchically porous materials can be used for the sensing of organic solvents as the emission is highly depended on the solvent environment;the lanthanide emission being quenched in the presence of acetonitrile and THF, but greatly enhanced in the presence of methanol.
文摘Three Eu（III） ternary complexes, Eu（hfa-H）3（Phen）, Eu（hfa-H）3（Bipy） and Eu（hfa-H）3（Bath） （hfa = hexafluoroacetylacetonate, Phen = 1,10-phenanthroline, Bipy = 2,2＇-bipyridine, Bath = bathophenanthroline）, were synthesized. Their luminescent properties were studied by incorporating deuterated Eu（III） complexes in a poly（methylmethacrylate） （PMMA） matrix, and the results indicated that luminescent PMMA including Eu（hfa-D）3（Bath） showed promising results for applications to novel organic Eu（III） devices, such as the high-power laser materials. Additionally, all the three Eu（III） complexes exhibited good thermostabilization.
基金Project supported by Zhejiang A & F University Science Foundation (2009FR068)the Education Department of Zhejiang Province (Y201119787)
文摘Two novel luminescent Eu（III） complexes with the formulas（NIP）Eu（DBM）3 1 and（ENIP）Eu（DBM）3 2(NIP=2-（naphtha-len-1-yl）-1H-imidazo [4,5-f] [1,10] phenanthroline,ENIP=1-ethyl-2-（naphthalen-1-yl）-1H-imidazo [4,5-f] [1,10] phenanthroline,DBM= dibenzoylmethanato) were successfully synthesized and characterized by IR and elemental analysis.The UV-vis absorption spectra and pho-toluminescence properties of the complexes were investigated,and the irradiation at the absorption band between 300-400 nm of europium complexes either in solution or in the solid state led to the emission of a sharp red band at;10 nm,a characteristic Eu3+ emission due to the transition of 5D0→7F2.Furthermore,the weak emission bands around 587 and 595 nm attributed to 5D0→7F0 and 5D0→7F1 transition were also displayed in the emission spectra.These results demonstrated that the Eu（III） ion was sensitized efficiently by the ligand and displayed photoluminescence with high intensity,narrow half-peak width,and monochromic light.The excited-state lifetimes of 1 and 2 were in the microsecond time scale,but the photoluminescence quantum yield of 2（0.03） was two times higher than that of 1（0.01） which should be at-tributed to the effect of the ethyl substituting in ENIP.
文摘以2-噻吩乙醛酸(HL)为第一配体,红菲绕啉(Bath)为第二配体合成了一种新型Eu(Ⅲ)三元配合物.采用等离子体原子发射光谱(ICP)、元素分析、FT-IR和1 H NMR表征了配合物的组成及结构.通过热重(TG)和发光光谱研究了配合物的热稳定性与发光性能.结果表明,该配合物分子式为EuL3Bath·2H2O,具有良好的热稳定性.在最佳激发波长(270nm)的紫外光照射下,该配合物能发出Eu(Ⅲ)离子很强的特征红光,其中电偶极跃迁(5 D0→7F2,613nm)发射最强;此外,该配合物还表现出相对较长的衰减寿命(τ=1.17ms).
基金supported by the National Natural Science Foundation of China(20971061,20871062 & J0630962)
文摘Eu(III) adsorption on rutile was investigated as a function of contact time,pH,ionic strength and Eu(III) concentration by using a batch experimental method.The effects of carbonate,sulfate,and phosphate were also studied.It was found that the kinetics of Eu(III) adsorption on rutile could be described by a pseudo-second-order model.The adsorption of Eu(III) on rutile is strongly pH-dependent,but relatively insensitive to ionic strength.A double layer model (DLM) with two inner-sphere Eu(III) surface complexes was applied to quantitatively interpret the adsorption of Eu(III) on rutile.There were no apparent effects of carbonate and sulfate on Eu(III) adsorption,whereas the presence of phosphate promoted Eu(III) adsorption on rutile.The surface complexes of Eu(III) on rutile were evidenced by X-ray photoelectron spectroscopy (XPS).
