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E. V. Chubarova D. G. Samsonenko H. G. Platas F. M. Dolgushin A. V. Gerasimenko M. N. Sokolov Z. A. Starikova M. Yu. Antipin V. P. Fedin 《Journal of Structural Chemistry》2004,45(6):1004-1013
Compounds of trigonal cluster chloroaqua complexes with cucurbit[8]uril were synthesized by slowly evaporating HCl solutions of chalcogenides heterometallic cubane cluster complexes of molybdenum and tungsten with cucurbit[8]uril in air; the complexes were characterized by X-ray diffraction analysis: (H3O)8[Mo3S4(H2O)2.5Cl6.5]2Cl(PdCl4)·(C48H48N32O16)· 29H2O (a = 13.3183(17) Å, b = 13.7104(18) Å, c = 18.225(3) Å; α = 80.263(3)°, β = 77. 958(3)°, γ = 87.149(4)°, V = 3207.4(7) Å3, space group P
, Z = 1, ρ(calc) = 1.900 g/cm3), (H3O)4 [Mo3S4(H2O)3Cl6]2·(C48H48N32O16)3·68H2O (a = 21.413(6) Å, c = 49.832(10) Å; γ = 120°, V = 19788(8) Å3, space group R
, Z = 3, ρ(calc) = 1.695 g/cm3), (H3O)6 [Mo3S4(H2O)3Cl6]2Cl2·(C48H48N32O16)·12H2O (a = 15.881(2) Å, b = 17.191(2) Å, c = 23.276(4) Å; β = 98.865(15)°, V = 6278.7(15) Å3, space group P21/c, Z = 2, ρ(calc) = 1.638 g/cm3), [W3S4(H2O)5Cl4]2·(C48H48N32O16)3·35H2O (a = 21.038(3) Å; α = 61.20(1)°, V = 6762.0(14) Å3, space group R
, Z = 1, ρ(calc) = 1.582 g/cm3). The [Mo3S4(H2O)3Cl6]2− anion complex was isolated as three geometrical isomers.Original Russian Text Copyright © 2004 by E. V. Chubarova, D. G. Samsonenko, H. G. Platas, F. M. Dolgushin, A. V. Gerasimenko, M. N. Sokolov, Z. A. Starikova, M. Yu. Antipin, and V. P. Fedin__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 1049–1058, November–December, 2004. 相似文献
13.
本文论述了WO_3薄膜氢离子敏器件的结构、原理、制备技术和测试分析。利用WO_3薄膜在H+溶液中由绝缘转化为导电特性,成功地研制成氢离子敏器件。这是一种简易而经济的微型pH敏器件技术。 相似文献
14.
15.
CO2氧化丙烷脱氢MoO3-V2O5/SiO2催化剂研究 总被引:4,自引:0,他引:4
采用表面改性和等体积浸渍法制备了MoO3-V2O5/SiO2复合氧化物,采用TPR、IR、TPD和微反技术表征了催化剂对CO2和C3H8的吸附性能和CO2部分氧化丙烷脱氢的反应性能.结果表明:随MoO3加入量的增加,V=O还原温度降低,晶格氧更易活化.CO2和丙烷的活化温度降低,丙烷转化率增高,丙烯选择性下降.V=O中晶格氧的活化是CO2氧化丙烷制丙烯反应的关键. 相似文献
16.
Four new compounds having nine cluster electrons and cores of the types Mo3OCl3, Mo3OBr3, and W3OCl3 are reported. Compound (1) prepared by reduction of [Bu4N][Mo3OCl6(OAc)3] in THF with metallic zinc, was shown by X-ray crystallography to be Mo3OCl4(OAc)3 (THF)2 (1). It forms crystals in space groupP21 with unit cell dimensionsa=9.472(2) Å,b=13.546(4) Å,c=9.652(2) Å, =101.70(2)°,V=1201(1) Å3,Z=2. The [Mo3(3-O)(-Cl)3]4+ core is surrounded by three -O2CCH3 anions, one Cl–, and two THF and has Mo-Mo distances of 2.620(1) Å, 2.613(1) Å, and 2.530(1) Å, with the shortest bond between the two Mo atoms to which the THF molecules are coordinated. Compounds [Bu4N]2 [Mo3OBr6(O2CCH3)3] · Me2CO, (2) and [Mo3OBr3(O2CCH3)3(PMe3)3]3 · BF4, (3) are the first two nine-electron Mo3 species with a [Mo3(3-O) Br3]4+ core. Both were obtained by zinc reduction of [Mo3OBr6(O2CCH3)3]– in the presence of (NBu4) Br (2) or PMe3 and NaBF4 (3), and each was characterized crystallographically. Compound (2) crystallized in space group Cc with unit cell dimensionsa=25.037(5) Å,b=12.827(2) Å,c=21.484(4) Å, =122.96(1)0,V=5790(3) Å3,Z=4. While the anion has no crystallographically required symmetry, its virtual symmetry is C3v
. The Mo-Mo distances are 2.619(2) Å, 2.610(3) Å, 2.644(2) Å, with a mean value of 2.624[14] Å. Compound (3) crystallized in space groupP21/c with unit cell dimensionsa=10.846(2) Å,b=25.033(5) Å,c=12.641(5) Å, =94.74(2)0,V=3420(2) Å3,Z=4. The cation occupies a general position but has virtual C3v
symmetry, with Mo-Mo distances of 2.601(2) Å, 2.610(2) Å, 2.627(2) Å, with a mean value of 2.613[14] Å. Thus the anionic and cationic Mo3 clusters in (2) and (3), respectively, have average Mo-Mo distances that are equal within experimental error. Compound (4), [NEt4]2 [W3OCl6(O2CCH3)3] is the first 9-electron compound of this type containing tungsten. It was prepared by reduction of [Et4N][W3OCl6(OAc)3] in benzene with Na/Hg. It crystallized in space groupP212121 with unit cell dimensionsa=11.076(2) Å,b=14.345(2) Å,c=21.026(3) Å,V=3574(1) Å3,Z=4. The anion resides on a general position but has virtual C3v
symmetry, with W-W distances of 2.577(1) Å, 2.612(1) Å, 2.584(1) Å and a mean value of 2.591[15] Å. 相似文献
17.
The 2,5-dimethylthiophene (2,5-Me2T) ligand in the isomers Cp*Ir(η4-2,5-Me2T) (1) and Cp*Ir(C,S-2,5-Me2T) (2) is activated to react with the dimers Cp(CO)2M?M(CO)2Cp[M?Mo (3), W (4)] to give complexes (5,6) in which the thiophene is coordinated to three metals. Oxidation of 5 with Cp2Fe+ removes the Mo dimer to give Cp*Ir(η5-2,5-Me2T)2+. Reaction of 5 with CO displaces the Mo as [CpMo(CO)3]2 to give Cp*Ir(CO)(C,S-2,5-Me2T) (7). Ultraviolet photolysis of 1 provides a convenient route to the ring-opened isomer 2. Despite the remarkable nature of the thiophene coordination in 5 and 6, its reactivity does not suggest new pathways that would lead to the hydrodesulfurization of thiophenes. 相似文献
18.
Vladimir L. Kolesnichenko Victor B. Rybakov Leonid A. Aslanov Sergei V. Volkov 《Journal of Cluster Science》1997,8(1):27-45
Thioselenohalide complexes Mo2(μ-S2)2Cl6(SeCl2)2 (I), Mo2(μ-S2)2Br6(SeBr2)2 (II), and W2(μ-S2)2Br6(SeBr2)2 (III) were synthesized by the reactions of corresponding metal halides or carbonyls or molybdenum metal with excesses of S2 X 2+Se2 X 2 mixtures. The complex W2(μ-S2)2Cl6(SeCl2)2 (IV) was obtained by an exchange reaction between (III) and excess of Se2Cl2. Coordination of the neutral SeX 2 ligands to thiohalidesM 2(μ-S2)2 X 6 results in higher thermal stability, and suggests the possibility to synthesize SeX 2 complexes of the unstable parent tungsten thiohalides. An unusual oxidative addition reaction of (I) was detected: {fx27-1} Both (I) and (IV) were characterized by X-ray crystal structure analysis. They are isostructural and form discrete molecules. Bridging S 2 2? ligands are coordinated perpendicularly to the metal-metal bond;d(M?M)=2.8066 Å and 2.793 Å for I and IV, respectively. Nonequivalence of chlorine atoms which are bound to the metal atom, relate to nonequivalence of halogen atoms in the complexesM 2(μ?S2)2 X 8 2? . Chlorine atomstrans to SeCl2 ligands form short bonds with the metal; the corresponding35Cl NQR frequency is increased. The selenium dichloride ligand is ambidentate. The selenium atom binds as a donor to the metal and as an acceptor to two chlorine atoms which are also bound covalently to the same metal atom. 相似文献
19.
以正硅酸乙酯(TEOS)为硅源,十六烷基三甲基溴化铵(CTAB)为表面活性剂,仲钨酸铵为钨源,采用水热晶化法一步合成了不同钨含量(以Si、W物质的量比nSi/nW表示)的WO3-MCM-48,然后经甲烷/氢气(V/V=1/4)混和气体程序升温还原碳化(TPC),制备出了WxC-MCM-48(x=1、2)催化剂,采用XRD、N2吸附-脱附和NH3-TPD对样品的结构进行了表征,用噻吩作为模型化合物,对WxC-MCM-48催化剂的加氢脱硫催化活性进行了评价。结果表明,在一定钨含量的条件下,WO3-MCM-48和WxC-MCM-48样品仍然保持MCM-48的三维立方有序介孔结构,nSi/nW=30~15时,碳化钨的物相为W2C;nSi/nW=7.5时,碳化钨为W2C和WC物相,WxC-MCM-48催化剂表现出了良好的加氢脱硫催化性能。 相似文献
20.
三核钨钼簇合物对苯乙烯氧化反应的催化 总被引:2,自引:0,他引:2
关于烯烃的催化氧化,报道较多。Takao等研究了苯乙烯在Ir和Rh络合物存在下的氧化反应;Collman曾报道环己烯在Vaska络合物[IrX(CO)(PPh_3)_2]催化下氧化成环己酮和环已烯氧化物。本文采用Cotton合成的簇合物[W_3O_2(CH_3CO_2)_6(H_2O)_3]Br_2· 相似文献