New molecular precursors for the formation of V-Mg multicomponent oxides by sol-gel process

In order to investigate molecular precursors of V-Mg system which has interesting catalytic properties, [VOCl(OR)]₂, Mg(OR)₂ and V₂Mg₂(O)₂(OH)₅Cl(OR)₃(ROH)₂ [OR = OCH(CH₃)CH₂OCH₃] are synthesized and characterized by ¹H, ⁵¹V NMR, IR, SM, ESR, elemental analysis and/or single crystal X-ray diffraction. The hydrolysis behaviour of each complex is investigated. For the heterometallic alkoxide, an orange-brown sol is obtained, studied by TGA and DTA and generates after calcination at 800°C, V₂MgO₅ and MgCO₃ identified by XRD.     

黑海参多糖组成的研究

通过酶降解、酒精沉淀、DEAE柱纯化和脱色精制四步，从黑海参体壁中制得黑海参多糖的纯品。经电泳法及凝胶拉法鉴定，所得样品为均一组分，是一种典型的动物酸性杂多糖，内含硫酸酯基。样品经水解后用HPLC检测，得葡萄糖（36．7％）、岩藻糖（16．4％）、葡萄糖醛酸（34．2％）、木糖（7．22％）及一些未知成分（5．47％）。经Smith降解及一些波谱特征表明，单糖之间苷键是α-型，主要为1-2和1-3连结。凝胶往法测定其平均分子量约是96×104。     

卡托普利合成工艺改进及有关物质合成

以(2S)-1-(3-巯基-2-甲基-1-氧代丙基)-L-脯氨酸为起始物料,经水解、盐析、精制合成了卡托普利,总收率85%,纯度99.72%,单杂小于0.1%。基于该工艺合成了卡托普利的5种杂质,纯度均大于95.0%,结构经1H NMR,13C NMR和HR-MS(ESI)确证。     

N,N′,N″,N''''''''''''-四对甲苯磺酰1,4,7,10-四氮杂环十二烷的微波常压快速水解

N ,N′ ,N″ ,N 四对甲苯磺酰 1,4,7,10 四氮杂环十二烷是Atkins法合成 1,4,7,10 四氮杂环十二烷的关键中间体 ,但其水解脱磺酰基比较困难 ,常规水解一般需要采用 96%～ 98%硫酸在 14 0℃左右加热 2～ 3d .报道了一种微波促进快速水解法 ,即在稍加改装或未改装的家用微波炉中 ,采用 95 %～ 98%硫酸 ,控制火力 2～ 5档 ,全对甲苯磺酰化全氮冠醚仅需5 0～ 12 0s即可完成水解 ,比常规加热水解所需时间缩短约 3 0 0 0～ 80 0 0倍 ,浓硫酸用量也比常规加热水解少 ,收率较常规水解高 .     

Raman Spectroscopy of Aqueous ZnSO4 Solutions under Hydrothermal Conditions: Solubility, Hydrolysis, and Sulfate Ion Pairing

Raman spectra have been measured for aqueous ZnSO₄ solutions under hydrothermal conditions at steam saturation to 244°C; solubility has been recorded as a function of temperature from 25 to 256°C. The high-temperature Raman spectra contained two polarized bands, which suggest that a second sulfato complex, possibly bidentate, is formed in solution, in addition to the 1:1 zinc(II) sulfato complex, which is the only ion pair identified at lower temperatures. Under hydrothermal conditions, it was possible to observe the hydrolysis of the zinc(II) aquo ion by measuring the relative intensity of bands due to SO ₄ ^2– and HSO ₄ ^– according to the equilibrium reaction Zn(OH₂)₆]²⁺ + SO ₄ ^2– [Zn(OH₂)₅OH]⁺ + HSO ₄ ^– The precipitate in equilibrium with the solution at 210°C could be characterized as ZnSO₄ · H₂O (gunningite) by x-ray diffraction (XRD) and Raman and infrared spectroscopy. At 244°C the equilibrium precipitate could be identified as ZnSO₄ (zincosite).     

Formation of “monodispersed” SnO2 powders of various morphologies

Several procedures for the preparation of colloidal SnO₂ powders, consisting of particles of narrow size distribution and of various morphologies, are described. The hydrolysis of SnCl₄ aerosols in the presence of gaseous ammonia produces poorly crystalline SnO₂ spheres of modal diameters <2 m. Depending on the preparation conditions, the forced hydrolysis of acidic (HCl) SnCl₄ solutions yields either prismatic particles or spherulites composed of tiny, strongly aggregated, elongated subunits. In both cases the particles are in the nanometer size range (<100 nm) having crystalline rutile structure. Rod-like SnO₂ particles (0.3 m) of good crystallinity can be obtained by hydrolysis of SnCl₄ solutions in the presence of formamide. It is concluded that the hydrolysis of dissolved SnCl₄ tends to produce elongated SnO₂ particles which, depending on the experimental conditions, may be at different aggregation states.     

Characterization of silicone phases by alkaline hydrolysis and CGC analysis

A simple way to elucidate the functional group substitution on silicone chains is presented. The polymer is decomposed into its monomers by alkaline hydrolysis. These monomers are converted into trimethylsilyl derivatives, which are then analyzed and identified by capillary gas chromatography/mass spectrometry.     

氧比铝基催化剂上羰基硫和二氧化碳的水解研究 Ⅱ.催化剂上CO_2-TPD的研究(英文)

利用ＣＯ２程序升温脱附测定了三种氧化铝基催化剂上的表面碱性。结果表明，三种催化剂上表面碱性的类型、强度和数目分布不同。活性氧化铝上负载Ｋ２Ｏ和Ｐｔ可大大改变催化剂表面碱性分布。三种催化剂上弱碱性中心的ＣＯ２脱附表现活化能分别为２５．９７，２７．９２和２９．７７ｋＪ／ｍｏｌ。弱碱性中心是ＣＯＳ水解催化活性中心，而弱的和较强的碱性中心参与ＣＳ２的水解催化反应。     

提高纤维素酶水解效率和降低水解成本

在我国可大量转化乙醇的是纤维质材料。纤维质材料转化乙醇的关键问题是纤维质转化为糖的过程,提高纤维素酶转化效率的方法有:(1)对纤维质材料进行预处理;(2)研究纤维素酶的最适作用条件;(3)纤维素酶的重复利用;(4)合理的发酵工艺等。本文分析了纤维素的结构以及纤维素酶的作用方式,总结了目前研究较多的几种纤维质材料预处理方法,及其对纤维素酶水解率的影响,并对研究纤维素酶的最适作用条件、纤维素酶的重复利用以及合理的发酵工艺进行了综述和分析。     

17-次乙二氧基-3-甲氧基-雌甾-2,5(10)-二烯-11β-醇用硅胶支持的草酸试剂选择性水解

以3-甲氧基一雌甾-1,3,5(10)-三烯衍生物,经Birch还原所得的3-甲氧基-雌甾-2,5(10)-二烯,是合成各种19-去甲甾体药物的重要前体,在甾体有机合成中有重要意义。在强酸条件下,水解3-甲基烯醇醚,将发生5(10)-双键移位,得到相应的共轭4-烯-3-酮化合物,同时,分子中的其他对酸敏感的基团会