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821.
Reaction of anhydrous YbC13 with 2 equiv, of sodium 2,4,6-tri-tert-butylphenoxide (ArONa, Ar=C6H2-t-Bu3-2,4,6) and 2 equiv, of potassium diphenyl amide in THF afforded the first bis(aryloxo) amido-lanthanide complex of (ArO)2Yb(NPh2)2K(THF)4 (1). In 1, the ytterbium and potassium were bridged via diphenyl amido ligands.The ytterbium metal center was coordinated to two oxygen atoms of aryloxide ligands and two nitrogen atoms of diphenyl amido ligands in a conventional distorted tetrahedral fashion, while the potassium interacted in η^2-fashion with two phenyl rings of the diphenyl amido ligands besides four THF molecules. 1 displayed moderate catalytic activities for the polymerization of methyl methacrylate and acrylonitrile. 相似文献
822.
N,N',N",N"'-四对甲苯碘酰-1,4,7,10-四氮杂环十二烷的微小常压快速水解 总被引:5,自引:0,他引:5
N,N',N",N"'-四对甲苯磺酰-1,4,7,10-四氮杂环十二烷是Atkins法合成1, 4,7,10-四氮杂环十二烷的关键中间体,但其水解脱磺酰基比较困难,常规水解 一般需要采用96%-98%硫酸在140 ℃左右加热2-3d。报道了一种微波促进快速水解 法,即在稍加改装或未改装的家用微波炉中,采用95%-98%硫酸,控制火力2-5档, 全对甲苯碘酰化全氮冠醚仅需50-120 s即可完成水解,比常规加热水解所需时间缩 短约3000-8000倍,浓硫酸用量也比常规加热水解少,收率较常规水解高。 相似文献
823.
The title compound (C17H16O2, Mr = 252.30) crystallizes in the monoclinic system,
space group P21/c with a = 11.5763(14), b = 11.0321(11), c = 11.5094(13) (A),β = 114.581(3)°, V=
1336.7(3) (A)3, Z = 4, Dc = 1.254 g/cm3, μ(MoKa) = 0.081 cm-1 and F(000) = 536.00. The final R
and wR are 0.0527 and 0.1285, respectively for 3058 observed reflections (I > 2σ(I)). In the title
molecule, two phenyl rings are rotated oppositely with respect to the central part C(1)-C(2)=C(3)-
C(4) (plane 3) and the dihedral angle between them is 14.8°. The phenone O(1) atom deviates from
plane 3 by 0.291(A). In the crystal the molecules form H-bond chains of R21(6) and R21 (5) types
similar crystals are also presented. 相似文献
824.
Reactions of 1,3-diisopropylcarbodiimide with alkali metal amides, MN(SiMe3)2 (M=Li or Na) in hexane or THF produced the alkali metal guanidinates { (i-PrN)2C [N(SiMe3)2]Li }2 (1) and { (i-PrN)2C[N(SiMe3)2]Na(THF) } 2 (2) in nearly quantitative yields. Both complexes 1 and 2 were well characterized by elemental analysis, IR spectra, ^1H and ^13C NMR spectra, and X-ray diffraction. It was found that the guanidinates adopt different coordination modes in these complexes. 相似文献
825.
Two new 15-memhored fimctionalized macrocycles, dioxo-polyazacydoalkanes with three pendant acetato groups, have been synthesized by the condensation reaction of DTPA dianhy-dride (DTPA = diethylenetrlamlnepentaacetic acid ) with 1,2-di-amlnopropane, ( 15-DTPA-1, 2-pn), or 1, 2-diaminocydohex-ane, (15-DTPA-1,2-cy). Their lanthanide complexes [ Ln ( 15-DTPA-1,2-pn)(H2O)]2[Ln= Eu (1), Gd (2)] and [Ln(15-DTPA-1,2-cy)(H2O)]2[Ln= Eu (3), Gd (4)] were also pre-pared. Single crystal X-ray diffraction analyses of complexes 2 and 4 show that they have dimeric structures in solid state;each metal ion is nine-coordinated in a distorted tricapped-trig-onal prism. In complex 4, the coexistence of two diastereoiso-meric molecules in the crystal lattice was observed. 相似文献
826.
Two ligand bridged binuclear titanium complexes Ti2(bppda)3(NMe2)2·3THF (1) and Ti2(bppda)3(NEt2)2·3THF (2) and one bis-ligand coordinated mononuclear complex Ti(bppda)2 (3) (ligand- HEbppda=N,N'-Bis(2-pyrrylmeth- ylidene)-1,2-phenylenediamine) were synthesized by adjusting the ratio of the starting materials and the reaction speed. The complexes were fully characterized with NMR, elemental analysis and X-ray crystal diffraction. The catalytic activity of the complex 1 to phenylacetylene hydroanilination reaction was also investigated. 相似文献
827.
通过控制反应条件和调节反应起始物的配比,合成了两个配体桥连的双核钛配合物 Ti2(bppda)3(NMe2)2•3THF (1) 和Ti2(bppda)3(NEt2)2•3THF (2) 及一个双配体配位的钛配合物 Ti(bppda)2 (3) (H2bppda =N,N'-Bis(2-pyrrylmethylidene) -1,2-phenylenediamine))。用核磁共振,元素分析及X-射线单晶衍射表征了化合物的结构,并研究了配合物 1 对苯乙炔氢化胺化反应的催化作用。 相似文献
828.
829.
The characteristic L1, Lα, Lβ and Lγ x-rays of Au and energy shifts produced by 20-50 MeV ^16O^5+ beams on a thick Au film are measured with a Si (Li) detector. Cross-section ratios of σ(Ll)/σ(Lα), σ(Lβ)/σ(Lβ) and σ(Lγ)/σ(Lα) versus O^5+ energy show that consistent calculations yield considerably better agreements. Energy shifts L1, Lα, Lβ and Lγ x-rays of Au target increase with more incidence energy. The main application for these measurements is multi-element trace analysis through particle induced x-ray emission. 相似文献
830.
对一类模型参考自适应控制映射进行了稳定性分析,通过使用中心流形简化和范式方法以及计算机辅助计算讨论了该类系统在参数空间内的所有1-余维和2-余维分岔行为及其性质,全面了解了系统在不同参数区域内的动态.从而为如何选取此类控制系统的参数以避免导致控制失效的多吸引子共存或长期存在的瞬态等动力学行为提供了方法和理论依据,并为在线调整参数以避免控制失效指明了方向. 相似文献