硅钨酸催化合成苯甲醛1,2-丙二醇缩醛

以硅钨酸为催化剂,通过苯甲醛和1,2-丙二醇反应合成了苯甲醛1,2-丙二醇缩醛。实验结果表明,硅钨酸对缩醛反应具有较高的催化活性,反应的最佳条件为：苯甲醛150mmol,n(苯甲醛)：n(1,2-丙二醇)：1.0：1.5,催化剂0.7％(反应物料总质量),带水剂环己烷8mL,反应温度85℃～125℃,反应时间1．0h,收率达88．9％．     

PMA‐SiO2: A Heterogenous Catalyst for O‐, S‐, and N‐Nucleophilic Substitution Reactions of Aryl Propargyl Alcohols

Aryl‐propargylic alcohols undergo O‐, S‐, and N‐nucleophilic substitution reactions in the presence of a catalytic amount of PMA‐SiO₂.     

Dodecatungstophosphoric Acid (H3PW12O40): A Novel and Efficient Recyclable Catalyst for Synthesis of 1,1‐Diacetates from Aromatic Aldehydes in Solvent‐Free System and Their Deprotection

A facile and efficient method for the formation of 1,1‐diacetates from a variety of aldehydes in the presence of a catalytic amount of H₃PW₁₂O₄₀ and acetic anhydride was achieved in good yields at room temperature. The deprotection of the resulting acylals is achieved using the same catalyst in acetone.     

Catalytic Synthesis of Fused 1,4-Dihydropyridines and 1,4-Dihydropyridine Derivatives Using Preyssler Heteropolyacids Catalyst

An efficient and convenient method for the synthesis of 1,4-dihydropyridines from β-dicarbonyl compounds, aldehydes, and ammonium acetate and the synthesis of fused 1,4-dihydropyridines from dimedone in the presence of Preyssler heteropolyacid catalyst are reported under reflux conditions with good to excellent yields. Preyssler heteropolyacid catalyst is easily prepared, stable (up to 300 °C), reusable, efficient, green and inexpensive.     

TEMPERATURE PROGRAMMED DESORPTION-MASS SPECTROMETRY STUDY OF NO DESOrPTION AND DECOMPOSITION BY TITANIA SUPPORTED 12-TUNGSTOPHOSPHORIC ACID

Titania supported 12-tungstophosphoric acid was examined for NO temperature-programmed desorption and decomposition. More than 90 % of absorbed NO decomposed into N₂ without evident desorption of O₂.     

杂多酸催化合成丙烯酸-2-乙基己酯

杂多酸（盐）作为性能优良的酸性、氧化性或二者兼具的双功能催化剂应用在许多有机合成反应中［１］，其中有些反应已成功实现了工业化［２］，因此近年来有关杂多酸（盐）催化反应的应用研究倍受关注．丙烯酸２乙基己酯（简称ＨＡ）是重要的高分子单体，与其它单体进...     

A Novel Synthesis of Polyaniline Doped with Heteropolyacid and its Special Property

Polyaniline doped with heteropolyacid was synthesized using solid-state synthesis method.XRD pattern showed that polyaniline molecule has highly ordered arrangement. Fluorescence property of the polyaniline meterials was found.     

Composite polymer electrolyte membranes comprising triblock copolymer and heteropolyacid for fuel cell applications

Hybrid organic/inorganic composite polymer electrolyte membranes consisting of a triblock copolymer (tBC) and varying concentrations of heteropolyacid (HPA) were investigated for application in proton exchange membrane fuel cells (PEMFC). An ABC triblock copolymer, that is, polystyrene‐b‐poly(hydroxyethyl acrylate)‐b‐poly (styrene sulfonic acid), PS‐b‐PHEA‐b‐PSSA, at 28:21:51 wt % was synthesized via atom transfer radical polymerization (ATRP) and solution‐blended with a commercial HPA. Upon the incorporation of HPA into the tBC, the symmetric stretching bands of both the SO group (1187 cm^?1) and the ? OH group (3440 cm^?1) shifted to lower wavenumbers (1158 and 3370 cm^?1). The shift in these FTIR absorptions suggest that the HPA particles strongly interact with both the sulfonic acid groups in the PSSA domains and the hydroxyl groups in the PHEA domains. When the weight fraction of HPA was increased to 0.2, the room‐temperature proton conductivity of the composite membrane increased from 0.048 to 0.065 S/cm, presumably because of the intrinsic conductivity of the HPA particles and the enhanced acidity of the sulfonic acid in the tBC. The water uptake of the composite membranes decreased from 130 to 48% with an increase of the HPA weight fraction to 0.4. The decrease in water uptake is likely a result of the decrease in the number of available water absorption sites because of the hydrogen bonding interaction between the HPA particles and the tBC matrix. Scanning electron microscopy and transmission electron microscopy images showed that the HPA nanoparticles with a diameter of 200–300 nm were uniformly distributed throughout the tBC matrix up to an HPA weight fraction of 0.4. Thermal stability of the composite membranes (decomposition temperature > 400 °C) was enhanced as compared with the pristine tBC membrane, presumably because of the strong specific interaction of the HPA particles with the sulfonic acid and hydroxyl groups. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 691–701, 2008     

纳米SiO2负载Preyssler杂多酸催化剂对水杨酸与苄醇或脂肪醇酯化反应的催化性能

An efficient and environmentally benign procedure for the catalytic esterification of salicylic acid with aliphatic alcohols, CnH2n+1OH(n=1-5)and benzylic alcohols,RC6H4CH2OH(R=H,NO2,OCH3,Br,Cl,Me)was developed using nano-SiO2-supported Preyssler heteropolyacid both under thermal conditions and microwave irradiation.Silica nanostructures were obtained through a sol-gel method and were characterized by transmission electron microscopy and powder X-ray diffraction.The effects of various parameters such as solvent type,molar ratio of substrates,Preyssler heteropolyacid loading on silica,catalyst amount,temperature,and reaction time were studied and the optimum conditions were obtained.It has been found that the catalyst with 30 wt%loading is highly active and shows high yields in esterification reactions.The use of nano-SiO2-supported Preyssler heteropolyacid coupled with microwave irradiation allows a solvent-free,rapid(3 min),and high-yielding reaction.This catalyst can be easily recovered and reused for many times without a significant loss in its activity.