Activation of trimethylsilyl cyanide by potassium phthalimide for facile synthesis of TMS-protected cyanohydrins

Potassium phthalimide was found to be a highly effective and easily accessible organocatalyst for the cyanosilylation of various carbonyl compounds under extremely mild conditions. The corresponding cyanohydrin trimethylsilyl ethers were obtained in high to quantitative yields in solvent-free conditions at room temperature using 2.5 mol% catalyst loading.     

KZnF3：Eu的水热合成及其光谱性质

采用中温水热法合马了立方钙钛矿单相ＫＺｎＦ３及ＫＺｎＦ３：Ｅｕ，通过ＳＥＭ观察了产物形态．ＸＰＳ测定结果表明，产物含氧量不高。荧光光谱及ＥＳＲ谱表明，ＫＺｎＦ３：Ｅｕ体系中Ｅｕ＾２＋与Ｅｕ＾３＋共存，进一步讨论了不等价取代中的电荷补偿途径。     

The effect of pH on the separation of manure nutrients with reverse osmosis membranes

This paper reports on the effect of pH on the retention of dry matter (DM), total ammonia-nitrogen (TAN), potassium, phosphorus and volatile fatty acids (VFAs) during the filtration of pretreated swine manure by three highly selective reverse osmosis (RO) membranes. The manure was pretreated using various combinations of biological and physical technologies, namely anaerobic digestion (AD), vacuum filtration through diatomaceous earth (DE), nanofiltration (NF), and a first stage RO filtration. The objective was to establish the level of acidification required to optimize permeate quality while minimizing chemical addition.     

离子液体反应介质中3-羟基丙酸甲酯加氢反应研究

以室温离子液体[Bmim]PF6作为反应介质,研究了四羰基钴钾K[Co(CO)4]催化3-羟基丙酸甲酯(3-HPM)加氢制1,3-丙二醇(1,3-PDO)的反应,并对反应条件进行了优化.同有机溶剂作为反应介质相比,该体系具有更高的选择性和更好的催化活性,并且产物经水萃取便可实现催化体系的回收利用.在反应温度165℃、氢气压力10.5 MPa、反应时间10 h、咪唑为促进剂的较佳反应条件下,3-HPM的转化率可达99.4%,1,3-PDO的收率可达82.9%,催化剂重复使用3次,1,3-PDO的收率不低于70%.并根据实验结果,提出了可能的催化反应机理.     

Clean one-pot synthesis of 1,2,4-oxadiazoles under solvent-free conditions using microwave irradiation and potassium fluoride as catalyst and solid support

Potassium fluoride was found to be an efficient catalyst and solid support for the synthesis of 3,5-disubstituted-1,2,4-oxadiazoles. In this work, a one-pot method for the synthesis of these compounds from the reaction of nitriles with hydroxylamine hydrochloride and acyl chloride in the presence of potassium fluoride under solvent-free conditions using microwave irradiation has been developed. The advantages of using potassium fluoride as a solid support in comparison to conventional solid supports are simple operation and convenient separation of the products.     

One-pot three-component synthesis of α-aminonitriles using potassium hexacyanoferrate(II) as an eco-friendly cyanide source

An efficient and environmentally friendly method has been developed for the synthesis of α-aminonitriles via one-pot three-component condensation of carbonyl compounds, amines, and potassium hexacyanoferrate(II) in the presence of benzoyl chloride as a promoter. This protocol has the features of use of eco-friendly cyanide source, high yield, and simple work-up procedure.     

Synthesis, characterization and enhanced photoconductivity from a mesoporous titania on dye doping

New wormhole-like mesoporous TiO₂ material has been synthesized through a convenient sol-gel method in the presence of a Schiff base secondary amine hexadecyl-2-pyrrole-methylamine (HPMA) containing chelating donor sites as template or structure directing agent (SDA). SDA molecules can be easily removed from the composite to generate mesoporosity and upon removal of the SDA molecule, this mesoporous TiO₂ material showed very high surface area (480 ± 10 m²/g) with an average pore diameter of 2.57 ± 0.05 nm. When Rose Bengal dye is entrapped inside the nanopores of this material, it showed a drastic enhancement (ca. 40-folds) in the photoconductivity vis-à-vis mesoporous TiO₂ alone under white light illumination.     

Synthesis and Crystal Structure of the Palladium(IV) Polyoxomolybdate,K0.75Na3.75[PdMo6O24H3.5]·17H2O

The first example of a heteropolyoxomolybdate containing palladium(IV) was isolated and characterized by X‐ray crystallography. The palladium(IV) hexamolybdate, K_0.75Na_3.75[PdMo₆O₂₄H_3.5]·17H₂O, was isolated from an aqueous solution at pH 4.5 in the space group P\bar{1} , a 10.790(2), b 12.244(3), c 14.086(3) Å, α 113.77(1), β 90.41(1),γ 107.86(1)°, and the structure was determined using X‐ray diffraction methods, refining to a residual of 0.0301 for 5334 reflections. A formal “[PdMo₆O₂₄H₃]^5–” subunit exhibits the basic Anderson structure, with two [PdMo₆O₂₄H₃]^5– cluster anions in the structure bridged by a hydrogen atom (formally an H⁺) situated on a center of symmetry to give a “[Pd₂Mo₁₂O₄₈H₇]^9–” dimeric anion. The palladium(IV) atom occupies a slightly distorted octahedral environment, with Pd–O distances ranging from 1.968 to 2.009 Å.     

Synthesis and characterization of graft copolymer (alginate-g-poly(N,N-dimethylacrylamide))

<正>The graft copolymerization of N,N-dimethylacrylamide onto alginate by free radical polymerization using potassium peroxymonosulphate-sarbose as a redox pair in an inert atmosphere was investigated.The reaction conditions for maximum grafting have been optimized by varying the reaction variables,including the concentration of N,N-dimethylacrylamide(7×10~(-2) mol/L to 23×10~(-2) mol/L),potassium peroxymonosulphate(2×10~(-3) mol/L to 18×10~(-3) mol/L),sarbose(0.4×10~(-3) mol/L to 3.4×10~(-3) mol/L),sulphuric acid(1×10~(-3) mol/L to 8×10~(-3) mol/L) and alginic acid(0.4 g/L to 1.8 g/L) along with time duration(60 min to 180 min) and temperature(25℃to 45℃).Water swelling capacity,metal ion sorption and flocculation studies of the synthesized graft copolymer have been performed.The graft copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis.     

甲基绿-高碘酸钾系统催化动力学光度法测定痕量铱(Ⅳ)

基于以H3PO4为反应介质,用HAc-NaAc(1+8)(pH5.7)作缓冲溶液,在沸水浴中加热条件下,痕量铱(Ⅳ)能灵敏地催化高碘酸钾氧化甲基绿的褪色反应,建立了一种测定痕量铱(Ⅳ)的新催化光度法。研究了反应的最佳条件。催化反应吸光度A与非催化反应吸光度A0的差值ΔA与铱(Ⅳ)的质量浓度ρ在0～2.0μg/25mL范围内呈良好的线性关系。检出限为2.97×10-10g/mL。对1μg/25mL铱(Ⅳ)测定的相对标准偏差为1.7%(n=11)。测定了动力学参数。该催化反应对铱(Ⅳ)为一级反应,总反应为准一级反应。反应的表观速率常数为4.613×10-4/s,表观活化能为40.56kJ/mol。该方法用于分子筛样品和活性炭中痕量铱(Ⅳ)的测定,回收率97.9%～104.4%。