Zeolite NaY-supported gold complexes prepared from Au(CH3)2(C5H7O2): reactivity with carbon monoxide

Mononuclear gold complexes in zeolite NaY were synthesized from initially physisorbed Au(CH₃)₂(C₅H₇O₂), and their reactions with CO in a flow system at 298 K and 760 Torr were investigated by infrared (IR) spectroscopy and mass spectral analysis of the effluent gases. CH₄ and CO₂ were formed as CO flowed through the sample either steadily or as successive pulses. The results are consistent with the inferences that (a) CO reacted with the supported gold to form gold carbonyls, (b) CH₄ formed by reaction of methyl groups on gold with traces of H₂O or hydroxyl groups on the zeolite and (c) CO on cationic gold reacted with traces of O₂ and/or H₂O to form CO₂. In samples treated in steadily flowing CO, cationic gold was reduced to zerovalent gold, but the cationic gold in samples exposed to CO pulses was not reduced to zerovalent gold, although CO₂ formed. Thus, CO adsorbed on cationic gold reacts to give CO₂ in the absence of zerovalent gold, consistent with the inference that gold catalysts for CO oxidation need not contain zerovalent gold.     

UV-Enhanced Exchange of O2with H2O Adsorbed on TiO2

Ultraviolet light dramatically increases the rate of isotope exchange between gas-phase O₂and water adsorbed on TiO₂at room temperature, but it does not affect the rate of CO₂–water exchange. Both ethanol and acetaldehyde, when coadsorbed with H₂¹⁸O, dramatically decrease the rate of O₂exchange, but not CO₂exchange, with adsorbed H₂¹⁸O. This decrease is attributed to a combination of competition for adsorbed oxygen between exchange and photocatalytic oxidation of the adsorbed organic and blocking of the oxygen adsorption sites by the organic. The same oxygen species participate in O₂-H₂¹⁸O exchange and photocatalytic oxidation.     

配合物La（C6H5CHOHC00）3（phen）（H2O）的合成

用苯羟基乙酸、邻菲罗啉与稀土的硝酸盐为原料合成了配合物La(C_6H_5CHOHCOO)_3(phen)(H_2O),通过元素分析、红外光谱、核磁共振等测试手段,确定了配合物的组成和结构,并通过热重分析对其热性质进行了表征。结果表明,配合物中邻菲罗啉以双齿螯合方式配位,而苯羟乙酸则以桥联或单齿方式参与配位。     

Preparation of a new type of half-sandwich (alkoxylalkylcyclopentadienyl)titanium trichloride complex and X-ray structural characterization of (CH3OCH2CH(CH3)C5H4)TiCl3

New substituted alkoxylalkylcyclopentadienyl titanium trichloride complexes, CH₃OCH₂CH(CH₃)C₅H₄TiCl₃ (3), CH₃OCH(CH₃)CH₂C₅H₄TiCl₃ (4) and CH₃OCH₂CH₂CH₂C₅H₄TiCl₃ (5) have been synthesized and 3 has been studied by X-ray diffraction. The crystal structure of 3 shows that there is an intramolecular coordination between the ethereal oxygen atom in the side chain on the Cp ring and the titanium atom with an average Ti–O bond length of 2.24 Å. Due to steric limitation around the coordination sphere of titanium, the oxygen atoms in the side chain in complexes 4 and 5 do not coordinate with the central metals.     

Syntheses and Characterization of Diorganotin Derivatives of 2-Mercapto-5-methyl-1,3,4-thiadiazole: X-ray Crystal Structure of Polymeric (C3H3S2N2) [(n-C4H9)6Sn3O(OH)2](C3H3S2N2)

Diorganotin derivatives of 2-mercapto-5-methyl-1,3,4 -thiadiazole, (R = Me 1, n-Bu 2, Ph 3, PhCH₂ 4), have been synthesized and characterized by IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy. Among them, polymer 2 was also characterized by X-ray crystallography diffraction analysis. This revealed that 2 showed a unique tricyclic structure consisting of a fused five-membered Sn₂ON₂ ring and a four-membered Sn₂O₂ ring. These formed a planar N₂Sn₃O₂ skeleton, with distorted trigonal bipyramidal coordination at the two tin centers and a distorted octahedral coordination at the other tin center. The supramolecular structure of polymer 2 was a 1D zig-zag polymeric chain stabilized by intermolecular O–H...S hydrogen bonds. An erratum to this article can be found at     

First X-ray crystal structure of cation [cis-Co(en)2(H2O)Cl]2+: Synthesis,spectroscopic and X-ray structural study of [cis-Co(en)2(H2O)Cl](C6H5SO3)2·H2O

A new cobalt(III) complex salt, [cis-Co(en)₂(H₂O)Cl](C₆H₅SO₃)₂ · H₂O] (I) has been synthesized and characterized by single crystal X-ray structure determination and NMR spectroscopy. This is a first report of the cobalt(III) cation in cis-configuration. The crystal lattice of the complex salt is stabilized by electrostatic forces of attraction and hydrogen bonding interactions.     

Synthesis,spectroscopic and structural aspects of triphenylantimony(V) complex with internally functionalized acetylferroceneoxime: Crystal and molecular structures of [C5H5FeC5H4C(CH3)NO]2SbPh3 and C5H5FeC5H4C(CH3)NOH

Triorganoantimony(V) complex (C₅H₅FeC₅H₄C(CH₃)NO)₂SbPh₃ (1) has been prepared by the reaction of Ph₃SbCl₂ with acetylferroceneoxime C₅H₅FeC₅H₄C(CH₃)NOH (2) in 1:2 molar ratio in anhydrous toluene. The complexes have been characterized by elemental analyses, IR and NMR (¹H and ¹³C) spectroscopic studies, and biologic activity was measured. And crystal structures of 1, 2 were reported. The coordination geometry around the antimony atom in 1 was slightly distorted trigonal bipyramidal with the carbon atoms of the SbPh₃ unit in equatorial positions and the two oxygen atoms of the oxime group occupying axial positions. The free oxime was clearly hydrogen bonded (H–N 2.10 Å/2.04 Å in 2) to essentially form a dimer.     

Synthesis and structure of a mixed valence metal carbitoxide complex: Eu3[O(CH2CH2O)2CH2CH3]4(OC6H3iPr2-2,6)3

The direct reaction of europium metal with HO(CH₂CH₂O)₂CH₂CH₃ followed by treatment with 2,6-ⁱPr₂C₆H₃OH leads to the crystallographically-characterizable, mixed valent carbitoxide product Eu₃[O(CH₂CH₂O)₂CH₂CH₃]₄(OC₆H₃ⁱPr₂-2,6)₃ (1), which contains bridging alkoxide ligands and both terminal and bridging aryloxide ligands.     

Acrolein Adsorption on Gold Clusters,A Theoretical Study of Conjugation Effect on C=C and C=O Interaction with Au Clusters

Abstract  

We studied acrolein (AC) adsorption on gold clusters Au _n (n = 1–5) using density functional theory. It is demonstrated that conjugation effect reduces the adsorbate–substrate interaction through π-(C=C), π-(C=O) and di-σ-(C=O) modes whereas it facilitates the di-σ-(C=C) and the σ-O configurations. Analysis reveals that in π-(C=C) and π-(C=O) modes acrolein uses the HOMO-1 orbital to interact with the clusters while in σ-O mode the HOMO of AC plays the role. For di-σ-(C=C), di-σ-(C, O) and di-(C=O), the HOMO orbital of the cluster donates electrons to acrolein. Acrolein adsorption through the C=C bond is more favorable than that via the C=O group, which explains why the yields of C=C hydrogenation is higher than that of C=O reduction.     

Single crystal structure of a heterometallic one-dimensional polymer: [{Cu(1,10-phen)}2(V2O4)(O3PCH2CH2CH2CH2PO3H)2(H2O)]n

A heterometallic one-dimensional polymer [{Cu(1,10-phen)}₂(V₂O₄)(O₃PCH₂CH₂CH₂CH₂PO₃H)₂(H₂O)]_n 1 (1,10-phen=1,10-phenanthroline) has been synthesized under hydrothermal conditions. The structure of 1 shows a stepped chain with two parallel 1,4-butylenediphosphonate ligands as linking units.     

Phase transitions in R2 SnCl6-type crystals (R = NH3 C2H3, NH3C2H5 and N(CH3)4)

The thermal dilatation in (NH₃ ·CH₃) SnCl₆, (NH₃ · C₂H₅) SnCl₆ and [N(CH₃)] SnCl₆ was measured, and as the results it has turned out that (NH₃ ⁶·C₂H₅) SnCl₆ and [N(CH₃)₄]₂ SnCl₆ undergo the first order transitions at 128 K and 158 K, respectively. The low temperature phases of (NH · C₂H₅) SnCl₆ and [N(CH₃)₄]₂ SnC1₆ are found to be monoclinic and tetragonal, respectively, No phase transition was observed in (NH₃ ·CH₃)₂ SnCl₆ down to 77 K.     

Trapping of CH3O formed from CO + H2

Methoxy formed on Al₂O₃ from¹³CO and H₂ coadsorption on Ni/Al₂O₃ was trapped by C₂H₅OH adsorption and temperature-programmed reaction (TPR). The presence of excess C₂H₅OH significantly increases the rate of¹³CH₃OH and (¹³CH₃)₂O formation. The¹³CH₃OH forms by the reaction of C₂H₅OH with¹³CH₃O on Al₂O₃. In the absence of C₂H₅OH,TPR following¹³CO and H₂ coadsorption did not produce significant amounts of¹³CH₃OHor(¹³CH₃)₂O.     

固相微萃取涂层材料CH2OCHCH2O(CH2)3-SBA-15的制备与表征

以甲基三乙酰氧基硅烷（γ-glycidoxypropyltrimethoxy silane, CH2OCHCH2O（CH2）3Si（OCH3）3; GPTES）为偶联剂,将醚基官能团接枝于SBA-15介孔分子筛孔道中,制备了无机-有机复合介孔材料CH2OCHCH2O（CH2）3-SBA-15,用小角X射线衍射,N2吸附-脱咐,元素分析,红外光谱和滴定法对复合材料进行了表征.结果表明,醚基有机基团成功接枝到SBA-15孔道内壁,而且SBA-15仍保持了有序的孔道结构.并研究了CH2OCHCH2O（CH2）3-SBA-15的萃取效能,结果表明,该涂层材料对多环芳烃有较高的萃取效率.     

Dielectric and dilatometric studies of (CH3)2NH2Ga(SO4)2 · 6H2O (DMAGaS)

The results of dielectric, pyroelectric, spontaneous polarization and dilatometric investigations in the temparature interval 110 K-295 K are presented for DMAGaS crystal. At both phase transition temperature, 136 K and 116 K, discontinuous changes of dielectric permittivity, spontaneous polarization and length of bars are observed. Temperature dependences of alongation along the ferroelectric direction and of spontaneous polarization are quite similar.