高效相转移法制备金属有机溶胶

Organosols of silver and gold nanoparticles stabilized by sodium oleate were prepared with high efficiency by simple phase transfer of their hydrosols to isooctane. Concentrations of sodium oleate and magnesium chloride have crucial effects on the phase transfer efficiency. UV-visible absorption spectroscopy and transmission electron microscopy have been used to characterize the nanoparticles. A possible phase transfer mechanism was proposed based on the anchoring positions of oleate deduced by molecular modeling calculations.     

Phase Transfer Catalyzed Method to Prepare Symmetrical Azobenzenes from Anilines

Using free radical 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxyl as catalyst, the phase transfer catalyzed method of oxidation of anilines to symmetrical azobenzenes with a saturated solution of potassium ferricyanide in 2N aqueous potassium hydroxide and dichloromethane is described for the first time. The reaction has an intimate relation with Hammett substituent constants. This report offers an efficient and rapid method to prepare azobenzenes, and a possible mechanism is also suggested.     

N,N-二烯丙基甲基胺的相转移催化合成

相转移催化剂;聚乙二醇-400;N;N-二烯丙基甲基胺的相转移催化合成     

Synthesis of Hydroxypropyl Guar Gum by Phase Transfer Catalysis

HGG (Hydroxypropyl guar gum) was synthesized by phase transfer catalysis for the first time. The effects of alkalinity, phase transfer catalyst, etherification, pH value, temperature,reaction time and stirring speed were investigated. An optimal synthetic reaction technology was established, namely, dose of guar gum is 100 g, propylene oxide 40-50 g, HTAC (hexadecyl trimethyl ammonium chloride ) 1.3-1.7 g, pH value 10-10.5, temperature 45-50~C, and reaction time 3-4 hours. The result shows that the improved HGG has high viscosity. Its dissolution speed, content of insoluble residue, colloid light transparency and stability are apparently superior to guar flour.     

相转移催化合成硫氰酸铵

以氨和二硫化碳为原料的传统合成硫氰酸铵 ( NH4 SCN)工艺分为加压法 [1,2 ]和常压法 [3,4 ] 2种 .常压法设备投资小 ,操作灵活 ,但常压因互不相溶的 CS2 、NH3两相反应体积小 ,速度慢 ,反应时间达 2 5 h以上 ,且 CS2 易挥发 ,使 NH4 SCN产率仅有 60 %左右 .表面活性剂作为相转移催化剂加快反应速度的应用已有报道 [5] .本文采用壬基酚四氧乙烯醚 ( OP- 4)和壬基酚二十一氧乙烯醚 ( OP- 2 1 )混合型催化剂用于 n( CS2 )∶ n( NH3) =1∶ 2 .5反应体系 ,在常温、常压及高速搅拌下 ,第 1步反应缩短为 4h,NH4 SCN产率提高到 70 %以…     

相转移催化法合成RAFT试剂

以苯为有机相,季铵盐为相转移催化剂,二硫代苯甲酸溴化镁分别与溴化苄、2-溴丁酸-2’-羟基乙酯及α-溴乙基苯反应,合成了三种不同结构的RAFT试剂——二硫代苯甲酸酯(3a～3c),收率82.7%～85.5%,其结构经1H NMR和IR确证。     

相转移催化制备高脱乙酰度壳聚糖

采用正丁醇-氢氧化钠反应体系,以十六烷基三甲基溴化铵为相转移催化剂,制得脱乙酰度为92％的壳聚糖。最佳反应条件为：甲壳素1．5g,反应温度120℃,反应时间2h,ω(催化剂)7％(以甲壳素的质量计),m(甲壳素)：m(NaOH)：m(醇)=1：3：16。     

Chemoselective Benzylation and Allylation of 4-Nitrobenzaldehyde Promoted by Phase Transfer Catalyst and Metal in Aqueous Media

Ｏｖｅｒｔｈｅｐａｓｔｔｅｎｙｅａｒｓ ,ｔｈｅｐｕｒｓｕｉｔｏｆｓｙｎｔｈｅｔｉｃｔａｒ ｇｅｔｓｗｉｔｈｉｎｃｒｅａｓｉｎｇｃｏｍｐｌｅｘｉｔｙｈａｓｒｅｓｕｌｔｅｄｉｎｔｈｅｄｅｖｅｌ ｏｐｍｅｎｔｏｆｒｅａｃｔｉｏｎｓｔｈａｔｅｍｐｈａｓｉｚｅｃｈｅｍｏ ,ｒｅｇｉｏ ,ｄｉ ａｓｔｅｒｅｏ ａｎｄｅｎａｎｔｉｏｓｅｌｅｃｔｉｖｉｔｙ .1 4 Ｔｈｅａｄｄｉｔｉｏｎｓｏｆｏｒｇａｎｉｃｈａｌｉｄｅｔｏｃａｒｂｏｎｙｌｃｏｍｐｏｕｎｄｓ ,ｐｒｏｍｏｔｅｄｂｙｖａｒｉｏｕｓｍｅｔ ａｌｓａｎｄａｃｉｄｃ…     

Mass Transfer Studies in the Hydrogenation of Methyl Oleate Over a Ni/SiO2 Catalyst in the Liquid Phase

A detailed mass transfer analysis was developed both theoretically and experimentally for the heterogeneously catalyzed hydrogenation of methyl oleate using a Ni/silica catalyst in a slurry reactor. The results indicate that, at the conditions studied, working with stirring rate between 1400 and 2000 rpm, catalyst particle size below 50 µm, and catalyst weight below 1.11 g assured the kinetic regime for the reaction.     

A One-pot Procedure to Prepare Ethynylferrocene and Iodoethynylferrocene

IntroductionFerrocene-containing compounds have been widely used as important probes to investigate the electron transfer/transport properties of the molecular materials1. Recently, this technique was employed in molectronics research, where the ferrocenes were incorporated on the ends of conjugated molecular wires, and the electron transfer/transport abilities of the molecular wires were conveniently studied by electrochemical method2. Ethynylferrocene and iodoethynylferrocene were two import…     

1,4-二乙氧基苯的相转移催化合成

采用大孔型交联聚苯乙烯为载体研制出新型季 钅盐型相转移催化剂Y98B ,并将其应用于 1 ,4-二乙氧基苯的催化合成反应 ,产品进行了红外光谱分析和熔点测定 ,探讨了催化剂用量、对苯二酚与溴乙烷物质的量比、反应温度和反应时间等动力学条件对产品收率的影响。确定了在反应温度为 70℃、对苯二酚∶溴乙烷 (摩尔比 )为 1∶3.5、反应时间为 4h、催化剂用量为 3.0g的条件下产品收率可达 84.3%     

手性相转移催化剂及其不对称催化反应

综述了手性季铵盐和手性冠醚两类手性相转移催化剂及其在不对称催化反应（包括加成，取代，氧化及还原等反应）中的应用，参考文献９７篇。     

疏水性相转移手性溶剂萃取分离叔丁喘宁对映体

以四苯硼钠 (NaBPh4)为疏水性相转移试剂 ,研究了叔丁喘宁对映体分别在含 13种不同烷基链的L 酒石酸酯手性选择体水 有机溶剂两相系统中的萃取分配行为 ,考察pH和有机溶剂对分配系数 (K)和分离因子 (α)的影响。实验表明 :BPh-4与叔丁喘宁对映体阳离子形成疏水性复合盐 ,促进叔丁喘宁对映体在有机溶剂中的溶解 ,提高了分配系数 ;L 酒石酸酯与叔丁喘宁对映体Ⅱ形成非对映体复合物的稳定性比与对映体Ⅰ形成的非对映体大 ;随着L 酒石酸酯烷基链的增长 ,分配系数和立体选择性增强 ;3类溶剂的萃取性能为醇>1,2 二氯乙烷 >烷烃 ,并随着醇碳原子数的增加 ,两对映体的分配系数和分离因子增大 ;pH值的影响很大。     

Solvothermal Route to Prepare the Metastable Phase 3c-Fe7S8 with Hexagonal Platelet Morphology

The metastable phase 3c-Fe7S8 with the hexagonal platelct morphology has been prepared by using solvothermal route.The product was characterized by mcans of X-ray powder diffraction(XRD) and transmission electron microscopy (TEM) and X-ray photoelectron speetra (XPS).The experiment results show that the as-prepared Fe7S8 is a metastable phase with the hexagonal platelet morphology.     

Phase transfer of platinum nanoparticles from aqueous to organic solutions using fatty amine molecules

In this report we demonstrate a simple process based on amine chemistry for the phase transfer of platinum nanoparticles from an aqueous to an organic solution. The phase transfer was accomplished by vigorous shaking of a biphasic mixture of platinum nanoparticles synthesised in an aqueous medium and octadecylamine (ODA) in hexane. During shaking of the biphasic mixture, the aqueous platinum nanoparticles complex via either coordination bond formation or weak covalent interaction with the ODA molecules present in the organic phase. This process renders the nanoparticles sufficiently hydrophobic and dispersible in the organic phase. The ODA-stabilised platinum nanoparticles could be separated out from hexane in the form of a powder that is readily redispersible in weakly polar and non-polar organic solvents. The ODA-capped platinum nanoparticles show high catalytic activity in hydrogenation reactions and this is demonstrated in the efficient conversion of styrene to ethyl benzene. The nature of binding of the ODA molecules to the platinum nanoparticles surface was characterised by thermogravimetry, transmission electron microscopy (TEM), X-ray photoemission spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR)     

Selectivity in the Ligand Functionalization of Photocatalytic Metal Oxide Nanoparticles for Phase Transfer and Self-Assembly Applications

The functionalization of photocatalytic metal oxide nanoparticles of TiO₂, ZnO, WO₃ and CuO with amine-terminated (oleylamine) and thiol-terminated (dodecane-1-thiol) alkyl-chain ligands was studied under ambient conditions. A high selectivity was observed in the binding specificity of a ligand towards nanoparticles of these different oxides. It was observed that oleylamine binds stably to only TiO₂ and WO₃, whereas dodecane-1-thiol binds stably only to ZnO and CuO. Similarly, polar-to-nonpolar solvent phase transfer of TiO₂ and WO₃ nanoparticles could be achieved by using oleylamine, but not dodecane-1-thiol, whereas the opposite holds for ZnO and CuO. The surface chemistry of ligand-functionalized nanoparticles was probed by attenuated total reflectance (ATR)-FTIR spectroscopy, which enabled the occupation of the ligands at the active sites to be elucidated. The photostability of the ligands on the nanoparticle surface was determined by the photocatalytic self-cleaning properties of the material. Although TiO₂ and WO₃ degrade the ligands within 24 h under both UV and visible light, ligands on ZnO and CuO remain unaffected. The gathered insights are also highly relevant from an application point of view. As an example, because the ligand-functionalized nanoparticles are hydrophobic in nature, they can be self-assembled at the air-water interface to give nanoparticle films with demonstrated photocatalytic as well as anti-fogging properties.     

The Synthesis of Symmetrical Azobenzenes from Anilines by Phase Transfer Catalysis

Azobenzeneshavebeenwidelyutilizedasdyesandanalyticalreagents'.Theycanals0beusedasmaterialofnon-linearoptics,0pticinformationstoringmateriaIinlaserdiskanddyeswithoilsolubilityinphotochromyinmoderntechnol0gy"'.TheoxidationofsubstitutedsemicarbazidestoazocompoundswithseveralreagentssuchasNBS(N-bromosuccinimide)/pyridine',KClO,M,S0'NeS0",DMF-NO.'and2,4,6-(t-C'H,),C,H,OWh,Fe(CN),/Nhasbeenreportedbyus.The0xidationofsubstitutedanilinestoazobenzeneswithavarietyofreagentssuchasphenyli0d0acet…     

超声辐射和相转移催化下肟苄醚的合成

在超声辐射和苄基十四烷基二甲基氯化铵作用下, 肟和苄基溴在NaOH水溶液中于室温反应30～60 min, 肟苄基醚的收率60%～96%, 反应时间短, 收率高, 对环境友好.     

相转移催化法合成对位和间位苯二甲酰基硫脲衍生物

酰基硫脲化合物;相转移催化合成;相转移催化法合成对位和间位苯二甲酰基硫脲衍生物     

聚乙二醇相转移催化法合成查耳酮

以聚乙二醇(polyethyleneglycol,PEG)为相转移催化剂进行了苯甲醛与苯乙酮的克莱森–施密特(Claisen-Schmidt)缩合反应,并就聚乙二醇用量、聚乙二醇相对分子质量和溶剂种类等影响因素进行了条件实验,在较优化的合成条件下,查耳酮产率可达80%。