共查询到20条相似文献,搜索用时 367 毫秒
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利用固相反应合成了Eu_(0.5)RE_(0.5)Fe_(0.5)Mn_(0.5)O_3(RE=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Y)等化合物。测量了其XRD谱及~(57)FeMssbauer谱.实验发现,随着RE原子序数的增加,样品的晶胞体积减小,Fe在化合物中处于Fe~(3+)的高自旋状态,~(57)Fe的四极裂矩与样品的畸变参数D成线性关系。 相似文献
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微波辐照下(Bi_2O_3)_(0.8)(La_2O_3)_(0.2)固熔体对甲烷氧化偶联的催化行为陈长林,洪品杰,戴树珊,阚家德(云南大学化学系,昆明,650091)关键词微波,甲烷氧化偶联,(Bi_2O_3)_(0.8)(La_2O_3)_(0.2)甲烷氧化... 相似文献
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利用固相反应合成了稀土取代的复合氧化物Eu_(0.5)RE_(0.5)Fe_(0.5)Mn_(0.5)O_3(RE=La,Pr,Nd,Sm,Gd,Tb,Dy,Ho,Er,Tm,Yb).测量了这些化合物的XRD和XPS谱。在XPS研究中发现,稀土取代而使稀土元素本身的结合能相对于其倍半氧化物中的有所降低;在取代的复合氧化物中,随着RE离子半径的减小,Fe、Mn的结合能随之增加。 相似文献
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Bis(cyclopentadienyl)samarium(II) has been shown to be insoluble in thf : ether mixtures, hence it cannot be isolated as a soluble product from the reaction of samarium with HgCp2 in thf : ether. 相似文献
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Masami Nakamoto Huub Koijman Martin Paul Wolfgang Hiller Hubert Schmidbaur 《无机化学与普通化学杂志》1993,619(8):1341-1346
The reaction of 1,2- and 1,3-benzenedithiol C6H4(SH)2 with chloro(phosphine)gold(I) complexes R3PAuCl (R = Et, Ph) in the presence of triethylamine in tetrahydrofuran gives stable gold(I) complexes 1,2-C6H4(SAuPR3)2 [R = Et ( 1 ) and Ph ( 2 )] or 1,3-C6H4(SAuPPh3)2 ( 3 ), respectively, in high yield. The compounds have been characterized by analytical and NMR spectroscopic data. From the reaction of 1,2-C6H(SH)2 with Et3P? AuCl a by-product [(Et3P)2Au]+ [Au(1,2? C6H4S2)2]? ( 4 ) has also been isolated in low yield. The crystal structures of compounds 2 and 4 have been determined by single crystal X-ray diffraction. The gold(I) atoms in complex 2 are two-coordinate with bond angles S? Au? P of 175.2(1) and 159.5(1)°, Au? S bond distances of 2.304(1) and 2.321(1) å, and a short Au…?Au contact of 3.145(1) Å. The gold(I) atom in the cation of complex 4 is also linearly two-coordinate with a P? Au? P angle of 170.1(1) Å and Au? P distances of 2.296(3) and 2.298(3) Å. The geometry of the anion in 4 shows a square-planar coordination of gold(III) by two chelating 1,2-benzenedithiolate ligands with Au? S distances between 2.299(3) and 2.312(3) Å (for two crystallographically independent, centrosymmetrical anions in the unit cell). 相似文献
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A simple and effective procedure for the enantioselective synthesis of (R)-and (S)-moprolol was described.The key step was the asymmetric synthesis of enantiopure (R)-and (S)-guaifenesin,which were synthesized from enantioenriched (R)-3-chloro-1,2-propanediol and (S)-epichlorohydrin via kinetics of hydrolysis resolution of racemic epichlorohydrin by chiral Salen-CoIIII complex.The e.e.values of both the optical compounds were above 98%,and the chemical structures of the target compounds were confirmed by 1H NMR,13C NMR,IR,and MS. 相似文献
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C60和C70等碳笼烯的发现及其在新物质、新材料等研究领域中的重要性,激励人们去探索合成更多新型多面体碳簇化合物与碳元素类似物[1,2].最近,两类新型多面体碳管笼烯的设想提出来了[3,4]应用HMO和MNDO方法对其稳定性变化规律、结构和成键特征进行了讨论.关于多苯的vanderWaals簇实验上已有广泛的调查[5,6],理论上对其二聚物(C6H6)。的不同几何构型与稳定性进行了深入的研究[7].本文采用abinitio计算有效势(effectivecorePotential)方法,对C12碳管元素簇和C12H12,碳管烷的平衡结构、稳定性和价键特征进行了理论预测.1… 相似文献
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手性二噁唑啉吡啶铁和镍配合物的制备与表征 总被引:1,自引:0,他引:1
Tridentate bis(oxazolinylpyridine)(1) reacted with nickel chloride or ferrous chloride in anhydrous ethanol to form bis(oxazolinylpyridine) Nickel(Ⅱ) and Iron(Ⅱ) complexes. The stable solid complexes were characterized with IR, UV, MS, XPS and elemental analysis. No stable complexes were formed with bidentate bis(oxazoline)(2) ins- tead of bis(oxazolinylpyridine). 相似文献
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Rhodium(III), palladium(II) and platinum(II) complexes of Bis(o-aminobenzenesulfonyl)ethylenediamine
New complexes of the formulae K3[RhL
3]·2 H2O, [PdL]·H2O and [M(LH2)Cl2] [whereM = Pd, Pt andLH2 = bis(o-aminobenzenesulfonyl)ethylenediamine] have been prepared and characterized by conductivity measurements, thermogravimetric analysis, X-ray powder patterns and IR, Ligand Field and1H-NMR spectroscopy.
Rhodium(III), Palladium(II)- und Platin(II)-Komplexe mit Bis(o-aminobenzolosulfonyl)ethylendiamin (Kurze Mitteilung)
Zusammenfassung Neue Komplexe der allgemeinen Formeln K3[RhL 3]·2H2O, [PdL]·H2O und [M(LH2)Cl2] mitM = Pd, Pt undLH2 = Bis(o-aminobenzolosulfonyl)ethylendiamin wurden dargestellt und mit Konduktionsmessungen, thermogravimetrischen Analysen, Röntgenstrukturanalysen, IR, Ligandfeld- und1H-NMR-Spektroskopie charakterisiert.相似文献
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O. V. Andreev M. N. Bochkarev T. V. Nekrasova A. V. Protchenko 《Russian Chemical Bulletin》1995,44(2):233-235
X-ray amorphous samarium(II) sulfide was prepared by the reaction of H2S with samarium(II) bis[bis(trimethylsilyl)amide] (1) in THF at 10–2 Torr. Compound1 was prepared by two methods: 1) the reaction of SmI2 with lithium bis(trimethylsilyl)amide and 2) the reaction of samarium naphthalide with bis(trimethylsilyl)amine. SmS was transformed to the polycrystalline state with the lattice parametera = 5.92 Å by annealing at 400–500 °C.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 241–243, February, 1995. 相似文献
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R. Ya. Kharisov R. R. Gazetdinov G. Yu. Ishmuratov G. A. Tolstikov 《Chemistry of Natural Compounds》2001,37(2):140-142
The versatile chiral synthon methyl (R)-5,5-dimethoxy-3-methylpentanoate has been prepared for the first time via ozonolytic decyclization of (R)-4-menthenone, which is available from L-(-)-menthol. The optically pure juvenoid (S)-(+)-hydroprene can be prepared from the synthon 相似文献
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Ali Kakanejadifard Toraj Hayati Azam Rezayat 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1511-1515
A series of Schiff bases containing four to six coordination sites N2S2 X2(X = O,N) 2-(2-(2-(aryl)methyleneamino)phenylthio)ethylthio)-N-((aryl)methylene)benzeneamine (2c–f) were prepared from the reaction of 1,2-di(2-aminophenylthio)ethane (1) with aromatic aldehydes. All compounds were characterized by means IR, mass, 1H and 13C NMR spectroscopy, and elemental analysis, and in the case of 2b with a single crystal X-ray diffraction. The X-ray crystal structure of 2b showed that the resonance occurs between aromatic rings, through the C=N bonds of the molecule. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
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Some novel (diorgano)chloro(4-chlorobutoxy)silanes were obtained by the reaction of dichlorodiorganosilanes with tetra hydrofuran in the presence of chloroplatinic acid.Translated fromIzvestiva Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 943–945, April, 1996. 相似文献