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1.
The structures of crystalline (over a wide temperature range) and molten rare-earth metal-LnCl3 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy) trichlorides are comprehensively studied by Raman spectroscopy.  相似文献   

2.
刘睦清  高忆慈 《稀土》2006,27(5):15-19
合成了2,3-二氯异丁酸根和4-甲基吡啶氮氧化物稀土三元配合物(RE=La、Ce、Pr、Nd、Sm、Eu).通过元素分析、红外、紫外、荧光、X射线粉末衍射、XPS、热分析以及摩尔电导等分析手段,确定了配合物的组成为[REL3(4-picNO)H2O](L= CH3C2H2Cl2COO -),并对它们的性质进行了讨论.  相似文献   

3.
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.  相似文献   

4.
利用循环伏安和极谱研究了Keggin结构钼钨硅杂多酸H4SiMo12-nWnO40(记为SiMo12-nWn,n=2,4,6,8,10)及其稀土衍生物K10H3〔Ln(SiMo6W5O39)2〕(记为Ln(SiMo6W5)2,Ln=La3+,Ce3+,Pr3+,Nd3+,Sm3+,Eu3+,Gd3+,Dy3+,Yb3+)在水溶液中的氧化还原性质,讨论了取代原子和酸度对杂多阴离子氧化还原性质的影响,探讨了极谱半波电位与pH的关系,并根据静电模型对杂多配合物的氧化还原规律性给予了合理的说明。  相似文献   

5.
Themetalcomplexesofhydrazideshaveattractedconsiderableinterestowingtotheirantifungalandantibacterialactivities[1 ,2 ] .Theycanalsobeusedasanalyticalreagents[3 ]andextractingagentsformetalsalts[4 ] .Manycomplexesofhydrazideshavebeensynthesizedandcharacterized[5]…  相似文献   

6.
A polyoxometalate K_(13)[Gd(GeW_(11)O_(39))_2]·34 H_2 O was synthesized and characterized by elemental analysis,IR spectroscopy, UV spectra, XRD and thermal gravimetric analysis. X-ray single-crystal structural analysis indicates that the title compound crystallizes in the triclinic crystal system. The heteropolyanion of [Gd(GeW_(11)O_(39))_2]~(13) consists of two [GeW_(11)O_(39)]~(8-) vacant Keggin moieties linked via Gd~(3+). Photocatalytic performance of K_(13)[Gd(GeW_(11)O_(39))_2]·34 H_2 O in photodegradation of X-3 B was also studied.When the reaction time is 180 min, the decoloring rate reaches 71.19%. With the decrease of pH, the decolorization rate increases gradually.  相似文献   

7.
A series of uhrafine K2Ln2Ti3O10(Ln = La, Ce, Pr, Nd, Sm, Eu, Dy)photocatalyst was prepared by microemulsion method based on tetrabutyl titanate reacting with potassium hydroxide and lanthanumoxide. The obtained products were characterized by XRD, TEM and UV-Vis spectra. These results indieate that highly ultrafine K2Ln2Ti3O10 can be accessible at lower fabricating temperature and shorter reation time by this approach. In addition, the investigation on their eatalytieal behavior based on the degradation of methyl orange under UV-Vis light suggests that the degradation rate can reach up to 60%.  相似文献   

8.
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.  相似文献   

9.
A separation procedure based on extraction chromatography using the di(2-ethylhexyl) phosphoric acid (D2EHPA) impregnated resin, anion exchange with DIAION SA 10 resin, and oxalate precipitation has been developed for the preparation of high-purity La2O3 in hydrochloric acid media at a high La concentration. The metallic impurities Ce, Pr, Nd, Sm, K, Mg, Ca, Zn, Cu, Co, Mn, Pb, Al, In, and Fe, but not Bi, were removed efficiently from La by extraction chromatography using a D2EHPA impregnated resin. The Bi was separated from the La by anion exchange (DIAION SA 10) separation. Thus, a high-purity LaCl3 solution was obtained by anion exchange separation and extraction chromatography. La2O3 was prepared from the purified LaCl3 solution by oxalate precipitation. Glow discharge mass spectrometry was applied for purity evaluation of the prepared La2O3. The purity of the prepared La2O3 was more than 99.9998 pct total rare earth oxide.  相似文献   

10.
通过感应熔炼制备La0.65RE0.10Mg0.25Ni3.55i0.15(RE =La,Ce,Pr,Nd,Sm)合金.采用X射线衍射方法分析了合金的相结构,研究了其电化学性能,并采用电化学阻抗谱分析了合金电极的放氢动力学特性.研究结果表明,合金是以LaNi5、LaNi3为主相的多相结构,同时合金中少量的Si元素与Mg和Ni元素形成了少量的Mg2 Si相和Ni2Si相.Ce,Pr,Nd,Sm部分替代La以后,合金的放电容量下降,Ce的替代使合金容量大幅度降低.对于本系列合金,La被其他稀土元素部分替代后,合金经过100次循环后的容量保持率略有下降,但除了Pr元素以外,变化值均较小.合金电极的电化学阻抗谱分析表明,中低频区的容抗弧半径依次为Ce >La> Nd >Sm >Pr,这表明采用Nd、Sm、Pr替代La后合金电极在碱液中放电过程电荷传递电阻Rct减小,即合金表面活性增加,但Ce替代却导致Ret急剧增大,这可能与Ce在碱液中易形成氧化物降低了合金的表面活性有关.  相似文献   

11.
双水杨醛1,6-己二胺希夫碱轻稀土配合物的合成和表征   总被引:4,自引:0,他引:4  
合成并表征了双水杨醛缩 1,6 己二胺希夫碱配体 (C2 0 H2 4 N2 O2 ,以L表示 )与轻稀土Ln3 的 7种新的固体配合物 [LnL2 ](NO3) 3(Ln =La、Ce、Pr、Nd、Sm、Eu、Gd)。利用元素分析、摩尔电导、红外光谱、电子光谱、X射线衍射物相分析、热分析方法进行表征。中心金属离子Ln3 与希夫碱配体中的亚胺氮和酚羟基中的氧发生配位 ,配位数为 8。  相似文献   

12.
Solidoxidefuelcells (SOFCs)haveseveraldis tinctadvantages ,e .g .,highenergyconversioneffi ciency ,wideadaptabilitytofuels ,theusageofnon preciousmaterials ,noliquids ,nocorrosions ,modularconstructionandmuchlowerproductionofNOx,SOxandnoise .Therefore ,theyreceiveincreasingatten tion[1,2 ] .AtypicalSOFCwhichutilizesyttria stabi lizedzirconia (YSZ)astheelectrolyterequireshighoperationtemperaturesuchas 10 0 0℃togainhighe noughionicconductivity .Loweringtheoperationtem peratureto 80 0℃wou…  相似文献   

13.
PreparationandCharacterizationofHeteropolytungstoarsenateComplexesContainingLanthanideElements¥WangWeiqing(DepartmentofChemic...  相似文献   

14.
Rareearthcomplexeswithsulfoxideandaromaticcarboxylacidhavebeenwidelystud ied[1~ 3 ] .Itisprovedthattheybothhavebet terfluorescencecharacter .Howeverthearo maticcarboxylofrareearthcomplexeshaveveryhighfluorescenceemissionintensityandstability ,butsolubilityi…  相似文献   

15.
Industrial and agricultural activities lead to the release of rare earth elements(REEs)in wastewater and aquatic ecosystems,and their accumulation in soils.However,the behavior of REEs in soils remains somewhat unclear.In the present work the fractionation and fixation of REEs in soddy-podzolic and chernozem soils spiked with La,Ce,and Nd chlorides were studied using dynamic(continuous flow)extraction,which allows natural conditions to be mimicked and artefacts to be minimised.The eluents applied are aimed to dissolve exchangeable,specifically sorbed,bound to Mn oxides,bound to metal-organic complexes,and bound to amorphous and poorly ordered Fe/Al oxides fractions extractable by 0.05 mol/L Ca(NO3)2,0.43 mol/L CH3COOH,0.1 mol/L NH2OH·HCl,0.1 mol/L K4P2O7 at pH 11,and 0.1 mol/L(NH4)2C2O4 at pH 3.2,respectively.It is found that the fixations of added La,Ce,and Nd in the form of metal-organic complexes is predominant for both types of soils:35%-38%in soddy-podzolic soil and 50%-79%in chernozem.The fixation of added elements in the first three fractions(exchangeable,specifically sorbed,and bound to Mn oxides)is significant for soddy-podzolic soil(5%-25%).For chernozem,the relative contents of added Ce and Nd in these fractions are nearly negligible.Only the content of exchangeable La is notable,about 5%.Adding any of three elements(La,Ce,or Nd)at the level of100 mg/kg to an initial sample results in changing the fractionation and bioaccessibility of other REEs present in soil.Their contents increase in the first three fractions and decrease in fifth(oxalate extractable)fraction for both soddy-podzolic soil and chernozem.The main difference is the behavior of REEs in pyrophosphate extractable fraction.For soddy-podzolic soil,adding La,Ce,or Nd results in decreasing the contents of other REEs associated with organic matter.For chernozem,on the contrary,the contents of REEs in the form of metal-organic complexes slightly increase.These processes may be attributed to competitive binding of elements and soil properties;they must be taken into account when assessing the environmental risks of soil pollution with REEs.  相似文献   

16.
The nitrate complexes of cerium, praseodymium and neodymium with 1,10-phenanthroline(phen) of general formula [Ln(phen)2(NO3)2(H2O)2]·NO3(where, Ln=Ce, Pr and Nd) were prepared and characterized by X-ray crystallography. Thermolysis of these complexes was investigated by simultaneous thermogravimetry(TG) and differential thermal analysis(DTA). Isothermal TG was taken to evaluate the kinetic parameters using model fitting as well as model free isoconversional methods. The thermolytic pathways were also suggested, which involves decomposition followed by ignition. All the three complexes had coordination number ten and showed multistep decompositions. In order to evaluate the response of rapid heating, ignition delay(Di) measurements were undertaken. The activation energies for ignition were found to decrease in the order: NdPrCe.  相似文献   

17.
Heteropolycompoundisanewcatalystwithmanyfunctionsinchemistryindustry .Itsexcellentcatalyticperformanceisdeterminedbyitscompositionandstructure .Ithassimplecompositionandfixedstructure ,althoughitmayconsistofmanyelements .Itsstructureandpropertycanbechang…  相似文献   

18.
SynthesisandCharacterizationofLn(NO3)3PhenFuTernaryComplexesLinJiyun(林纪筠),MaDejian(马德建)(DepartmentofChemistry,EastChinaNorm...  相似文献   

19.
A novel tungstosilicic polyoxometalate containing 5-fluorouracil and Nd,K26(C4H4FN2O2)8Nd(SiW11O39)4·SH2O(FNSW)was synthesized and its structure was characterized by using elemental analysis,FT-IR spectra,X-ray powder diffraction,UV-vis spectra and TG.The results indicated that the compound FNSW had Keggin structure of heteropolyanion and ring structure of 5-fluorouracil,and it had a good thermal stability.With 5-fluorouracil for the positive control group,the cytotoxicity tests in human renal embryonic cell HEK293 and the antitumor activity tests in hepatocellular carcinoma cell HepG-2 were carried out by the methyl thiazolyl tetrazolium method.The toxicity of the compound FNSW was lower than that of 5-fluorouracil,and compared with 5-fluorouracil the compound FNSW could inhibit HepG-2cell in vitro with significant difference.The rare earth clement Nd increased the biological activity of polyoxometalate significantly.  相似文献   

20.
快速准确测定地质样品中La、Ce、Pr、Nd、Sm,能够为寻找稀土矿物提供基础依据。实验在对样品粒度、样品的磨制方法优化的基础上,选取与待测样品粒度一致、基体相似、各元素含量有梯度且含量范围足够宽的岩石、土壤、水系沉积物、稀土和部分多金属系列标准物质作为校准样品,用综合数学校正公式校正谱线重叠干扰,实现了粉末压片-X射线荧光光谱法(XRF)对地质样品中轻稀土元素La、Ce、Pr、Nd、Sm的测定。实验表明,当样品粒度不小于160目(0.097mm)时,测定结果与电感耦合等离子体质谱法(ICP-MS)最相符;对60~80g样品用粉碎机磨制4min,过160目筛的过筛率为96.7%~98.5%,过筛率能满足地质标准(DZ/T 0130.2—2006)过筛率大于95%要求,筛上团聚颗粒轻磨后100%过160目筛。各元素的检出限如下所示:La 2.93μg/g、Ce 3.86μg/g、Pr 2.84μg/g、Nd 2.97μg/g、Sm 4.18μg/g。选择地质实际样品,按照实验方法分别重复制备7个样片,La、Ce、Pr、Nd、Sm测定结果的相对标准偏差(RSD,n=7)为0.81%~1.4%。选取4个地质样品,分别按照选定的方法对La、Ce、Pr、Nd、Sm进行测定,测得结果与参考值(电感耦合等离子体质谱法多次测量的平均值)吻合。取未参与校准由线回归的稀土、土壤、水系沉积物、岩石标准物质各一个,按照实验方法分别进行5次平行测定,计算各轻稀土元素的测定平均值,结果表明,测定值均在标准值误差允许范围内。  相似文献   

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