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121.
Annette Ostrowski Jrg Jeske Frank Ruthe Peter G. Jones Rainer Streubel 《无机化学与普通化学杂志》1997,623(12):1897-1902
Synthesis and Spectroscopic Characterization of some Pentacarbonyltungsten(0) Complexes with Various 1H-Phosphirene Ligands: Crystal Structures of , and The tungsten(0) complex 1 reacts upon heating with acetylene derivatives 2a–f in toluene to form benzonitrile and the complexes 4a–f ( 4a : R1 ? Ph, R2 ? H; 4b : R1 ? Ph, R2 ? CH3; 4c : R1 ? OEt, R2 ? H; 4d : R1 ? Ph, R2 ? CO2Et; 4e : R1, R2 ? CO2Me; 4f : R1, R2 ? SiMe3), which have been isolated by chromatography. Spectroscopic and mass spectrometric data are discussed. The crystal structures of the compounds 4a, b and d were determined by X-ray single crystal structure analysis ( 4a : space group P21/n, Z = 4, a = 937,5(2) pm, b = 2202,4(6) pm, c = 1266,3(4) pm, β = 108,94(4)°; 4b : space group P21/c, Z = 4, a = 1293,9(2) pm, b = 923,5(1) pm, c = 2223,4(3) pm, β = 92,385(6)°; 4d : space group P21/c, Z = 4, a = 955,2(2) pm, b = 3190,9(4) pm, c = 930,7(2) pm, β = 99,64(1)°). 相似文献
122.
Paul K. Baker Michael G.B. Drew Steve P. Gonsalves Archie W. Johans Margaret M. Meehan 《Journal of chemical crystallography》2002,32(5-6):113-118
[WI2(CO)3{Ph2P(CH2)2PPh2}] (1) crystallizes out in the monoclinic space group P21/n, with a = 13.852(7) Å, b = 14.789(19) Å, c = 14.915(19) Å, = 102.86(1)°, Z = 4. [WI2(CO)3{Ph2P(CH2)3PPh2}] (2) crystallizes out in the monoclinic space group P21/n, with a = 10.499(15) Å, b = 14.58(2) Å, c = 20.75(3) Å, = 103.59(1)°, Z = 4. Both structures show the metal in a seven-coordinate environment with a carbonyl in the unique capping position, two further carbonyls and a phosphorus in the capped face, and two iodides and the second phosphorus in the uncapped face. 相似文献
123.
The reaction of CuCl with WOCl3 at 400 °C leads to a mixture of Cu1?x[W2O2Cl6] ( 1 ) and Cu1?x[W4O4Cl10] ( 2 ) in form of black lustrous needles. Both compounds crystallize in space group C2/m with a = 12.7832(5) Å, b = 3.7656(2) Å, c = 10.7362(3) Å, β = 119.169(2)° for 1 and a = 12.8367(19) Å, b = 3.7715(7) Å, c = 15.955(3) Å, β = 102.736(5)° for 2 . The structures are made up of WO2Cl4 octahedra. In the case of 1 two octahedra are edge‐sharing via chlorine atoms to form pairs which are linked via the trans‐positioned oxygen atoms to form infinite double strands . In the structure of 2 two of these double strands are condensed via terminal chlorine atoms to form quadruple strands . Like for all members of the Mx[W2O2X6] structure family (X = Cl, Br) nonstochiometry with respect to the cations M was observed. The copper content of 1 and 2 was derived from the site occupation factors of the respective structure refinements. For several crystals examined the copper content varied between x = 0.27 and 0.17 for 1 and x = 0.04 for 2 . In both structures the oxochlorotungstate strands are negatively charged and connected to layers by the monovalent copper ions, which are tetrahedrally coordinated by the non‐bridging chlorine atoms of the strands. The structure models imply disorder of the Cu+ ions over closely neighboured sites. 相似文献
124.
Terminal alkynes do not partake in sequential [2+2+1]/benzoannulation reactions with Fischer carbene complexes and highly reactive and sterically hindered olefins; instead, they undergo a Fischer carbene complex-catalyzed Pauson-Khand reaction (PKR). This result has allowed the development, for the first time, of a tungsten-catalyzed PKR, although of limited scope. 相似文献
125.
Richard S. Herrick Christopher J. Ziegler Kerianne Crandall Ronald M. Jarret 《Journal of organometallic chemistry》2008,693(4):619-624
The one-pot reactions of ferrocenecarboxaldehyde, W(CO)4(pip)2 (pip = piperidine) and either 2-(aminomethyl)pyridine or 2-(2-aminoethyl)pyridine lead to clean formation of pyridine imine products W(CO)4(η2-NC5H4CHNCH2C5H4FeCp) (1) and W(CO)4(η2-NC5H4C2H4NCHC5H4FeCp) (2), respectively. Crystal structures of the two compounds show that in 1 the imine double bond has migrated so that it is conjugated with the pyridine ring while in 2 the imine double bond remains conjugated with the cyclopentadienyl ring. This finding is reinforced by a comparison of dihedral angles in each molecule. IR, NMR and electronic spectra each highlight the differences between the two compounds. Crystal data for C21H16FeN2O4W (1): monoclinic P2(1)/c, a = 12.768(2) Å, b = 13.593(2) Å, c = 12.981(2) Å, β = 119.46°, V = 1961.6(4) Å3, Z = 4; C22H18FeN2O4W (2): monoclinic P2(1)/c, a = 16.759(1) Å, b = 8.8612(7) Å, c = 13.802(1) Å, β = 95.998(1)°, V = 2038.4(3) Å3, Z = 4. 相似文献
126.
Zhen-Kang Wen 《Journal of organometallic chemistry》2008,693(7):1359-1366
The modification of bis(pyrazol-1-yl)methanes by organotin halide on the methine carbon atom has been successfully carried out, and their related reactions have also been studied. Bis(3,5-dimethylpyrazol-1-yl)(iododiphenylstannyl)methane [Ph2ISnCH(3,5-Me2Pz)2] can be obtained by the selective cleavage of the Sn-Csp2 bond in bis(3,5-dimethylpyrazol-1-yl)triphenylstannylmethane with I2 in a 1:1 molar ratio, while {di(tert-butyl)chlorostannyl}bis(3,5-dimethylpyrazol-1-yl)methane [(t-Bu)2ClSnCH(3,5-Me2Pz)2] and {di(tert-butyl)chlorostannyl}bis(3,4,5-trimethylpyrazol-1-yl)methane [(t-Bu)2ClSnCH(3,4,5-Me3Pz)2] are easily prepared by the reaction of the bis(3,5-dimethylpyrazol-1-yl)methide or bis(3,4,5-trimethylpyrazol-1-yl)methide anion with di(tert-butyl)tin dichloride. The molecular structure of [(t-Bu)2ClSnCH(3,5-Me2Pz)2] determined by X-ray structure analysis indicates that bis(3,5-dimethylpyrazol-1-yl)methide acts as a bidentate monoanionic κ2-[C,N] chelating ligand. Reaction of these bis(pyrazol-1-yl)methanes functionalized by organotin halide with W(CO)5THF results in the oxidative addition of the relative electrophilic Sn-X (X = Cl or I) bond instead of the Sn-Csp3 bond to the tungsten(0) atom, yielding new metal-metal bonded complexes R2SnCHPz2W(CO)3X (R = Ph or t-Bu, Pz represents substituted pyrazol-1-yl). Furthermore, treatment of the oxidative addition product (t-Bu)2SnCH(3,5-Me2Pz)2W(CO)3Cl with n-BuLi results in known complex CH2(3,5-Me2Pz)2W(CO)4 with the loss of the organotin fragment. In addition, reaction of Ph2ISnCH(3,5-Me2Pz)2 with 2-PySNa (Py = pyridyl) leads to the replacement of iodide by 2-PyS− anion to give Ph2(2-PyS)SnCH(3,5-Me2Pz)2, which subsequently reacts with W(CO)5THF to result in the decomposition of this ligand, also yielding the known bis(3,5-dimethylpyrazol-1-yl)methane derivative of CH2(3,5-Me2Pz)2W(CO)4. 相似文献
127.
W-ZSM-5催化剂C4烯烃裂解制丙烯催化性能研究 总被引:3,自引:0,他引:3
采用浸渍法制备了W-ZSM-5催化剂,用X-射线衍射(XRD)、N2吸附、NH3-TPD和H2-TPR等表征手段,研究了W的添加对HZSM-5催化剂物化性质的影响,并考察了W-ZSM-5催化剂在C4烯烃催化裂解制丙烯反应中的催化性能.结果表明,W的添加中和了催化剂的部分强酸位,降低了催化剂的酸性和酸强度,抑制了芳构化和氢转移等副反应的发生,增强了催化剂的抗积炭性能,促进了催化裂解过程中歧化反应的发生,有利于提高丙烯的选择性和收率.当W含量为3.2%时,催化剂的丙烯选择性和收率值达到最大,分别为47.4%和41.3%. 相似文献
128.
Florian Pachel Dr. Markus Ströbele Carl P. Romao David Enseling Thomas Jüstel Prof. Dr. Hans-Jürgen Meyer 《欧洲无机化学杂志》2023,26(19):e202300096
The new heteroleptic tungsten iodide cluster compound [W6I12(NCC6H5)2] is presented. The synthesis is carried-out from Cs2W6I14 and ZnI2 under solvothermal conditions in benzonitrile solution, yielding red cube-shaped crystals. [W6I12(NCC6H5)2] represents a heteroleptic [W6I8]-type cluster bearing four apical iodides and two benzonitrile ligands. Molecular [W6I12(NCC6H5)2] clusters form a robust hydrogen bridged crystal structure with high thermal stability and high resistibility against hydrolysis. The electronic structure is analyzed by quantum chemical methods of the calculated electron localization function (ELF) and the band structure. Photoluminescence measurements are performed to verify and describe the photophysical properties of [W6I12(NCC6H5)2]. Finally, the photocatalytic properties of [W6I12(NCC6H5)2] are evaluated as a proof-of-concept. 相似文献
129.
Michael Frotscher Wilhelm Klein Joseph Bauer Chang‐Ming Fang Jean‐Franois Halet Anatoliy Senyshyn Carsten Baehtz Barbara Albert Prof. Dr. 《无机化学与普通化学杂志》2007,633(15):2626-2630
The literature states different compositions (M/B = 1:2 vs. 2:5) and structures for diborides of molybdenum and tungsten. Using X‐ray and neutron powder diffraction as well as energy and wavelength dispersive electron microprobe analysis, the Mo/B and W/B systems were now reinvestigated. Molybdenum diboride crystallizes as a stoichiometric compound Mo2B4 (formerly described as Mo2B5) in space group (No. 166, a, b = 3.01375(2) Å, c = 20.9541(3) Å), and as a non‐stoichiometric compound MoB2?x (formerly described as MoB2) in P6/mmm (No. 191, a, b = 3.043(2) Å, c = 3.067(2) Å), whereas stoichiometric tungsten diboride W2B4 (formerly described as W2B5) is found to crystallize in space group P63/mmc (No. 194, a, b = 2.9864(4) Å, c = 13.896(2) Å). These results seem to be supported by DFT calculations which show the instability of a hypothetic W2B5. 相似文献
130.
The complexes [W(CO)5(Ph2SbX)], X = Cl (1), Br (2) and I (3) were prepared by reaction of [W(CO)5(tetrahydrofuran)] with Ph2SbX. The structures of 1-3 were studied by X-ray diffraction. In the crystals there are weak contacts between the oxygen atoms of the CO ligands and antimony atoms of neighbouring molecules. DFT calculations were carried out for 1 using gradient corrected functional B3LYP. The bonding between Ph2SbCl and the W(CO)5 fragment in 1 was analysed using charge decomposition analysis. 相似文献