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121.
以有机高价碘杂环化合物1,2为底物,在Pd(PPh3)2Cl2-CuCl催化剂存在下与末端炔烃进行交叉偶联反应,实验发现该反应为--化学选择性反应,控制反应体系的物料比、温度及反应时间可以分别得到单偶联或双偶联产物,从而证实了有机高价碘杂环化合物的碘盐在进行交叉偶联反应时的反应活性比sp2的碘化物高. 相似文献
122.
Solid state synthesis and structure of two novel polyoxometalates [(n-Bu)4N]4[M6O19][Ag2I4](M?Mo,W)†
Hou Hong-Wei Xin Xin-Quan Yu Kai-Bei Wang Zhe-Min Liu Shi-Xiong Huang Jin-Ling 《中国化学》1996,14(2):123-130
The reaction of [NH4]2[MO2S2], AgI and (n-Bu)4NBr in solid state produced the polyoxometalates [(n-Bu)4N]4[M6O19][Ag2I4] (1, M? Mo; 2, M? W) which were structurally determined. The crystals of 1 and 2 are isomorphous, monoclinic, space group P21/c. 1, a = l.6624(2), b=1.6699(3), c=l.7217(2) nm, β=98.29(1)°, V=4.729(1) nm3, Z=2, R=0.040, Rw“0.037; 2, a = 1.6636(3), b = 1.6733(3), c = 1.7190(3) nm, β=98.25(1)°, V=4.736(l) nm3, Z = 2, R = 0.038, Rw = 0.047. The results of the structure determination showed that the two compounds had the same structures whose skeletons are composed of [Ag2I4]2. and [M6O19]2-. The difference of them and heteropolymetalate compounds synthesized in solution is that the title compounds contain cluster. ion, heteropolymetalate and organic cations, while the latter is only composed of heteropolymetalate and organic cations. 相似文献
123.
O. M. Hemeda M. A. Henaish S. A. Olofa B. Y. Baradie A. Tawfik 《Journal of Thermal Analysis and Calorimetry》1992,38(10):2291-2299
Sodium acetylacetonate was prepared by the interaction of acetyl acetone with sodium hydroxide. The thermal conductivity, phonon velocity, mean free path, Yong's modulus, and the thermal expansion coefficient were studied. The thermal conductivity of the material decreases with increasing temperature due to the thermal lattice scattering of phonons. The velocity of phonons is also decreased due to the perturbation of thermal phonons. The linear thermal expansion coefficient increases with temperature due to the weakness of the attractive forces between the small Na+ cations and bulkier acetylacetonate anions in the lattice.
Zusammenfassung Natriumacetylacetonat wurde durch die Wechselwirkung zwischen Acetylaceton und Natriumhydroxid gewonnen. Es wurde die Wärmeleitfähigkeit, die Phononengeschwindigkeit, die mittlere freie Wegstrecke, das Elastizitätsmodul und der Wärmeausdehnungskoeffizient untersucht. Die Wärmeleitfähigkeit der Substanz nimmt wegen der thermischen Gitterstreuung der Phononen mit steigender Temparatur ab. Die Geschwindigkeit der Phononen nimmt auf Grund der Perturbierung der thermischen Phononen ebenfalls ab. Der lineare Wärmeausdehnungskoeffizient steigt mit zunehmender Temperatur an, was auf die schwachen Anziehungskräfte zwischen den kleinen Na+ Ionen und den massigen Acetylacetonat-Anionen im Gitter zurückzuführen ist.相似文献
124.
双-单齿芳香酰胺型配体桥联La3+一维配位聚合物的合成与晶体结构 总被引:2,自引:1,他引:2
通过硝酸镧和双-单齿芳香酰胺型配体L {L=1,4-双[(2'-苄胺甲酰基苯氧基)-甲基]苯}之间的反应得到了配位聚合物{[La(NO3)3]2•L3}n, 并用X射线单晶衍射测定了配合物的晶体结构. 配合物为三斜晶系, P1空间群, 晶胞参数a=1.1298(2) nm, b=1.2689(1) nm, c=2.1030(3) nm, α=81.189(9)°, β=80.95(1)°, γ=65.832(9)°, V=2.7032(6) nm3, Z=2, R=0.0267, wR=0.0679, La3+为9配位, 呈变形的三帽三角棱柱配位构型. 配合物通过配体的桥联作用形成一维环链相间的配位聚合结构, 由于相邻链间不存在氢键和π-π堆积作用, 所以配合物是以单链形式堆积排列. 相似文献
125.
Four lanthanide coordination polymers with benzophenone‐4,4′‐dicarboxylic acid (H2bpndc) and 1,10‐phenanthroline (phen), [Ln2(bpndc)3(phen)] (Ln=La (1), Pr (2) and Tb (3)), [Yb(bpndc)15(phen)].05H2O (4) were obtained through solvothermal synthesis. The crystallographic data show that 1, 2, and 3 are isostructural, the Ln(III) ions in 1, 2 and 3 are all eight‐ and ten‐coordinated, respectively, and thus the Ln(III) ions are connected by bpndc ligands, resulting in an interpenetrating 3D structure. While in 4, the Yb(III) ions are eight‐coordinated and connected by bpndc ligands into a 3D structure with 1D rhombic channels, which result from the effect of lanthanide contraction from La(III) to Yb(III) ions, and the bpndc ligands in 1, 2, 3, and 4 display three types of coordination modes. 相似文献
126.
Mujie Yang Xiaojun Zhang Jianfu Li Zhiquan Shen 《Journal of polymer science. Part A, Polymer chemistry》1992,30(1):63-69
The study of rare earth coordination catalysts for polymerization of 1-octene has been successfully carried out for the first time. Some features and kinetic behavior of polymerization of 1-octene by Nd(naph)3–AIEt3 catalyst system in tetrachloro-methane are described. The overall polymerization activation energy Ea measured was 74.5 kJ/mol and the rate equation could be expressed as Rp = kp [Nd] [M] (kp = 3.21 × 10?3 L/mol s, at 50°C). The catalytic activity of various rare earth elements in Ln (naph)3 and ligands in NdL3 for the polymerization was compared. A 1-octene oligomer with double bonds was obtained. It is either a white or pale yellow waxy semi-solid. Its number-average molecular weight is about 103 and the molecular weight distribution is less than 2. 相似文献
127.
The new layered ternary compound Nb3GexTe6 (x ? 0.90) was prepared by direct combination of the elements taken in the stoichiometric proportions 3 : 1 : 6, heated at 1 000 °C for 10 days in silica tubes and quenched to room temperature. The phase crystallizes in the orthorhombic symmetry, space group Pnma (#62), with the following single crystal refined parameters: a = 643.18(5) pm, b = 1391.98(11)pm and c = 1 154.07(5) pm, with Z = 4. The structure was refined to an R of 3.4% (Rw = 4.6%), with 1969 independent reflexions and 49 parameters. The structure is based on the close stacking of trigonal prismatic (TP) slabs in the AA/BB mode. The slabs can be seen as built up from face sharing biprisms, which are filled either by one or by two niobium cations situated in the middle of the trigonal prisms. The germanium is located in the middle of the common face of two prisms, leading to a rather unusual anionic square coordination. The refinements showed that this latter cation does not fill completely its square site. No cation was found in the van der Waals gap between the slabs. The mean dGe? Te distance (276.5 pm) is in agreement with GeII cations, while some Te …? Te distances (from 333.84 to 361.65pm) are too short for anions in a simple contact. These bonding distances, already mentionned in some MTe2 compounds, are to be ascribed to charge transfer in the structure, with a partial oxidation state for the tellurium anions. Short Nb? Nb and Nb? Ge distances (292.0 and 281.3 pm, respectively) imply intercationic bonding within the slabs. 相似文献
128.
Zhang JJ Sheng TL Hu SM Xia SQ Leibeling G Meyer F Fu ZY Chen L Fu RB Wu XT 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(16):3963-3969
The first successful attempt to construct 3D supramolecular frameworks with high-nuclear 3d-4f heterometallic clusters as a node is reported. The self-assembly of Ln3+, Cu2+ and amino acid in solution leads to the formation of two polymers, 35-nuclear complex [Sm6Cu29] 1 with a primitive cubic net-like structure and 36-nuclear complex [Nd6Cu30] 2 with a face-centred cubic network type structure. Glycine and L-proline, respectively, were used as ligands. It should be noted that 2 has a chiral framework. X-ray structure analyses show that 1 crystallizes in the triclinic P1 space group (a=19.6451(8), b=20.4682(8), c=20.7046(8) A, alpha=89.453(1), beta=66.290(1), gamma=68.572(1) degrees, V=7003.0(5) A3 and Z=1) and 2 belongs to the cubic P2(1)3 space group (a=b=c=32.4341(3) A, V=34 119.7(5) A3 and Z=4). Both complexes utilize Ln6Cu24 octahedral clusters as nodes and trans-Cu(amino acid)2 groups as bridges. Electrical conductivity measurements reveal that both polymers behave as semiconductors. 相似文献
129.
Eva BeckerChristian Slugovc Eva RübaChristina Standfest-Hauser Kurt MereiterRoland Schmid Karl Kirchner 《Journal of organometallic chemistry》2002,649(1):55-63
The synthesis and some reactions of the Ru(II) and Ru(IV) half-sandwich complexes [RuCp(EPh3)(CH3CN)2]+ (E=P, As, Sb, Bi) and [RuCp(EPh3)(η3-C3H5)Br]+ have been investigated. The chemistry of this class of compounds is characterized by a competitive coordination of EPh3 either via a RuE or a η6-arene bond, where the latter is favored when the former is weaker, that is in going down the series. Thus in the case of Bi, the starting material [RuCp(CH3CN)3]+ does not react with BiPh3 to give [RuCp(BiPh3)(CH3CN)2]+ but instead gives only the η6-arene species [RuCp(η6-PhBiPh2)]+ and [(RuCp)2(μ-η6,η6-Ph2BiPh)]2+. Similarly, the EPh3 ligand can be replaced by an aromatic solvent or an arene substrate. Thus, the catalytic performance of [RuCp(EPh3)(CH3CN)2]+ for the isomerization of allyl-phenyl ethers to the corresponding 1-propenyl ethers is best with E=P, while the conversion drops significantly using the As and Sb derivatives. By the same token, only [RuCp(PPh3)(CH3CN)2]+ is stable in a non-aromatic solvent, whereas both [RuCp(AsPh3)(CH3CN)2]+ and [RuCp(SbPh3)(CH3CN)2]+ rearrange upon warming to [RuCp(η6-PhEPh2)]+ and related compounds. In addition, the potential of [RuCp(EPh3)(CH3CN)2]+ as precatalysts for the transfer hydrogenation of acetophenone and cyclohexanone has been investigated. Again aromatic substrates are clearly less suited than non-aromatic ones due to facile η6-arene coordination leading to catalyst's deactivation. 相似文献
130.
利用离子阱质谱的原理和特点,研究了小分子醇、醚、胺、醛、酮等有机化合 物(分子量小于200)在离子阱里的分子离子反应,总结了反应特点和规律,并把 它归类为自身化学电离(SCI)反应。以丁酮、丙烯醇为例,采用FTMS对反应产物 离子进行准确质量测定,验证了它们各自的分子离子反应结果。另外,把该类化合 物(30个)SCI反应的质谱图与NIST98库中的标准EI质谱图进行了比较,建立了 SCI质谱图库,提高了在离子阱质谱上对这类小分子化合物定性分析的准确率。 相似文献