IR-spectroscopic studies of the interaction of propylene and acrolein with a CoMoO4 catalyst

IR spectra of propylene and acrolein adsorbed at different temperatures on CoMoO₄ supported on MgO were recorded. Four different surface species were found: a -complex, an oxygen bonded carbonyl complex, acrylic acid and a carboxylate type complex. The mechanism of their transoformation is discussed.

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- CoMoO₄ MgO. , 4 : -, , , . .

     

Catalytic isomerization of olefins on BeO, I

The catalytic activity of BeO for the double bond shift of 1-pentene has been investigated. The maximum activity was exhibited by samples calcined at 1173 K. The effect of pyridine, CO₂ and CCl₄ on the activity was also studied. Lewis acid-base site pairs appear to be active for the isomerization.

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BeO 1- . , 1173 . , CO₂ CCl₄ . - .

     

环氧丙烯酸酯的紫外光固化

制备了适于配制紫外光固化涂料的环氧丙烯酸酯，研究了反应温度、阻聚剂、催化剂等因素对环氧树脂与丙烯酸反应的影响；讨论了反应机理和动力学；并利用红外光谱观察了产物的紫外光固化行为。季铵盐能有效地催化环氧树脂和丙烯酸的反应，当其用量为０．６％～１．２％时，在９０～１１０℃反应４．５～８小时后，环氧基转化率大于９７％。由此配制的光固化涂料经紫外光辐照能快速固化。     

Extract-photometric determination of vanadium(V) with 3-indole-acetohydroxamic acid

Summary A spectrophotometric study has been carried out of the violet complex 3-indole-acetohydroxamic acid-vanadium extracted into a solution of trioctylmethyl-ammonium chloride in toluene [_max 525 nm; =5381 l mol^–1 cm^–1; stoichiometry 1:3 (metal:reagent)]. A new method for the extract-spectrophotometric determination of V⁵⁺ in the range of 2–7 g/g is proposed and interferences by foreign ions were investigated. The method has been satisfactorily applied to the determination of vanadium(V) in fuel oil. The relative error is ±2.9%.     

Triterpene glycosides of Astragalus and their genins. XXIV. Cycloorbicoside G from Astragalus orbiculatus

A bisdesmosidic glycoside — cycloorbicoside G — has been isolated from the epigeal parts of the plantAstragalus orbiculatus Ledeb. (Leguminosae), and on the basis of chemical transformations and spectral characteristics its structure has been established as (23R,24S)-16,23;16,24-diepoxycycloartane-3,7,25-triol 25-O--D-glucopyranoside 3-O--D-xylopyranoside.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 837–842, November–December, 1987.     

低温和低压下水热合成Na4Zr2(SiO4)3

以ZrOCl_2·8H_2O,Na_2SiO_3·9H_2O和NaOH为原料,在250℃约100bar的条件下,水热晶化合成出Na_4Zr_2(SiO_4)_3,并生长相应的单晶。讨论了水热反应及其条件.产物借助于XRD,Raman,~(29)Si MAS NMR以及阻抗谱技术进行了研究.结果表明产物具有与其他方法制备的Na_4Zr_2(SiO_4)_3相同的性质.     

烯胺酮与烯胺酯的交叉缩合反应及自缩合反应的区域选择性研究

烯胺酮与烯胺酯以(3C+3C)缩合反应形成多取代芳环化合物,具有区域选择性。用波谱和 X-射线衍射技术确定了产物的结构,讨论了反应机理。     

Hydrothermal Synthesis and Structural Characterization of a Tubular Arsenic-Vanadate: [CoII(2,2′-bpy)2]2[AsIII8VIV14O42(H2O)]·H2O

The hydrothermal reaction of VOSO₄, As₂O₃, CoC₂O₄·2H₂O and 2,2-bipy yields a novel arsenic-vanadate [Co^II(2,2-bpy)₂]₂[As^III₈V^IV ₁₄O₄₂(H₂O)]·H₂O (1), which is characterized by IR, elemental analysis, TGA, magnetic susceptibility and single crystal X-ray diffraction analysis. X-ray diffraction shows that compound 1 is the first example of tubular arsenic–vanadium cluster containing infinite {[Co(2,2-bpy)₂]₂[As₈V₁₄O₄₂(H₂O)]} chain constructed from [As₈V₁₄O₄₂(H₂O)] clusters interconnected through [Co(2,2-bpy)]²⁺ units. Crystal data: 1, orthorhombic, P 2₁2₁2₁, a=12.1401(2) Å, b=15.8722(1) Å, c=39.9533(5) Å, Z=4.Graphical Abstract: A novel polyoxoarsenicvanadate, [Co^II(2,2-bipy)₂]₂ [As^III₈V^IV ₁₄O₄₂(H₂O)]·H₂O, is depicted along with a tubular hybrid solid with a rhombic tube formed within the chain.     

Synthesis, Characterization and Conductivity of α-Keggin-type Nanoparticles, Co(en)_3PMo_(12)O_(40)·8H_2O with Optical Activity

IntroductionChirality is ubiquitous in the nature.Chiralcompounds have many applications in the areas ofmedicine,catalysis and materials,etc. Polyox-ometallates are inorganic polymers,which have at-tracted much interest since they have electri-cal[1_ 3 ] ,magnetic[4] ,optical properties[5_ 7] ,andsome characters as liquid crystals[8,9] .In this workwe report theα- Keggin structural polyoxometallatenanoparticles with optical activities.The opticalactivities of the samples are [α]13 D =+ 1 7…     

Ion-induced CO adsorption on polycrystalline nickel. Secondary ion mass spectrometry study

In the process of ion-induced CO adsorption (Ar⁺, 4 keV, 4 A/cm²) on polycrystalline Ni at room temperature and P=(1–40)×10^–6 Pa the emission of Ni⁺, NiCO⁺, CO⁺, NiO⁺ and C⁺ ions is observed. The emission of the last three ions is due to the ion-stimulated dissociation of weakly bound CO state and NiO formation. The weakly bound state is formed owing to surface defects produced by ion bombardment. The cross sections of the ion-induced desorption are 1.8 and 0.8×10^–14 cm², respectively, for weakly bound and strongly bound states.