一类新型的双β-氨基醇的合成及催化硼烷对芳酮的不对称还原反应

以L-半胱氨酸盐酸盐出发，经与二卤代烷偶联，成酯和格氏反应制得三种双手性β-氨基醇，1,2-双[R-2-氨基-3-羟基-3,3-二苯基丙硫基]乙烷(4a)，1,3-双[R-2-氨基-3-羟基-3,3-二苯基丙硫基]丙烷(4b)，1,4-双[R-2-氨基-3-羟基-3,3-二苯基丙硫基]丁烷(4c)。将此类双手性β-氨基醇与硼烷在THF溶液中反应，in situ制备双手性恶唑硼烷催化硼烷对芳酮的不对称还原，产物苯乙醇的光学收率达72.8%、α-溴代苯乙醇的光学收率达91.4%。     

乙酰螺旋霉素作为手性选择剂对手性药物的毛细管电泳拆分

毛细管区带电泳添加的手性选择剂常见的有环糊精类、蛋白质以及大环抗生素等[1].作者以乙酰螺旋霉素为手性选择剂,对两种手性药物进行了拆分研究,并初步讨论了部分操作参数的影响.     

细乳液聚合法制备磁性复合微球及其表征

在制备超细Fe3O4 磁性粒子的基础上 ,以 3种低分子量聚合物Disperbyk 1 0 6、Disperbyk 1 0 8和Disperbyk 1 1 1为Fe3O4 微粒在单体相中的分散稳定剂 ,采用细乳液聚合法制备了平均粒径为 3 40nm的PS Fe3O4 磁性复合微球 .详细研究了分散剂种类对细乳液聚合制备磁性复合微球的影响 ,并采用XRD、TGA和TEM等手段对磁性复合微球的形态、结构及磁响应性等进行了表征 .实验结果证明分散剂的选择对磁性复合微球的成功制备起着至关重要的作用 ,兼具酸性和碱性功能基的分散剂Disperbyk 1 0 6具有更好的分散和稳定效果 .TEM结果表明 ,所制备的复合微球具有一些缺陷 ,而缺陷处往往是Fe3O4 磁性粒子聚集的地方     

化学气相沉积法制备氧化锡自组装纳米结构

采用化学气相沉积法在镀有5-10 nm厚金膜的SiO2衬底上, 通过控制生长条件, 实现了二氧化锡纳米结构的自组装生长, 成功制备出了莲花状和菊花状的二氧化锡自组装纳米结构. 利用扫描电子显微镜、X射线衍射等表征分析手段对样品的表面形貌、结构及成份进行表征和研究. 并在此基础上, 讨论了两种自组装纳米结构的生长机制.     

冠醚化Schiff 碱配合物金属胶束催化BNPP水解动力学

研究了两种新的冠醚化Schiff 碱过渡金属配合物与表面活性剂Brij35(聚氧乙烯(23)十二烷基醚)形成的金属胶束对BNPP（对硝基苯酚磷酸二酯）的催化水解反应. 探讨了催化反应机理, 建立了一种金属胶束催化BNPP水解的动力学数学模型; 计算了模拟酶催化反应的相关参数和表观活化能. 结果表明, 此类金属胶束作为模拟水解金属酶对BNPP水解反应表现出良好的催化活性.     

Stereoselective Synthesis of (Z)-α,β-Unsaturated Ketones via Hydromagnesiation of Alkynylsilanes

α,β-Unsaturated ketones are important synthetic intermediates because of their versatile reactivities and many syn-thetic applications of them have been reported in the literature.[1] However, only a few methods for the synthesis of (Z)-α,β-unsaturated ketones are available. The palladium catalyzed coupling reactions of alkenyl copper reagents with acid chlorides afforded (Z)-α,β-unsaturated ketones.[2] The phase transfer catalyzed hydroacylation of allenes with carbon monoxide, decacarbonyldimanganese and methyl iodide gave (Z)-α,β-unsaturated ketones in a stereospecific process.     

聚碳硅烷的高温高压生成机理研究

分别以聚二甲基硅烷(PDMS)、液态聚硅烷(LPS)及PDMS裂解剩余物(LPCS)为原料,在不同的温度下高压合成聚碳硅烷(PCS),采用红外、紫外、核磁共振、分子量及其分布等分析PCS的组成、结构随温度的变化.同时,采用改变减压蒸馏温度的办法,对PCS进行分级,收集在不同蒸馏温度下的馏分,通过对一系列馏分进行了IR分析,以此推测PCS的转化过程.研究表明,PCS的生成过程是随着温度的升高,PDMS、LPS中键能较低的Si—Si键断裂,逐渐转变成为键能较高的Si—C键,转化为低分子的碳硅烷;随着温度的升高,碳硅烷分子间发生脱氢、脱甲烷缩合反应使产物的分子量逐渐长大,生成PCS.     

Physico-chemical Characterization of Mo-Hβ Zeolite Catalysts

A series of Mo-impregnated Hβ samples, with MoO3 loading in Hβ zeolite in the mass fraction range of 0. 5%-6.0%, were studied by means of XRD and IR in order to characterize their structures. Mo/Hβ sampies‘ crystallinity almost linearly decreases with increasing the amount of MoO3 loaded, The IR spectra and XRD patterns suggest that the progressive destabilization of the Hβ zeolite structure is caused by increasing Mo loading in (MoO3 Hβ zeolite). During the calcination, Al2(MoO4)3 formed from the dealumination of Hβ zeolite, causes the substantially partial breakdown of the zeolite framework when the Mo loading in MoO3 Hβ is relatively high.     

环氧化橡胶及其合金的研究与应用

综述了国内外环氧化橡胶及其合金的研究现状和应用趋势,重点介绍了环氧化天然橡胶、环氧化聚丁二烯、环氧化苯乙烯-丁二烯-苯乙烯三嵌段共聚物及其合金的优点,以及影响其物理机械性能的因素和环氧化橡胶的发展方向。     

SYNTHESES OF THE SOLUBLE,HIGH MOLECULAR WEIGHT AND LADDERLIKE POLYPH ENYLSILSESQUIOXAN E AND COPOLYMETHYLPHENYLSILSESQUIOXANES BY PREAMMINOLYSIS METHOD

Soluble, high molecular weight (MW) and ladderlike polyphenylsilsesquioxane (LPPSQ) and its copolymers, ladderlike random and block copolymethyiphenylsilsesquioxanes(LR-PMPSQ and LB-PMPSQ)have been prepared by preamminolysis, hydrolysis and polycondensation reactions. The preparation method can be carried out easily at the temperature below 95℃with high yield of 95 %, instead of the conventional way by using high-boiling solvent and any reaction activator or by precipitation with methanol. Three kinds of ladderlike polymers have been characterized. The MW's of the polymers reached to 10~6 without noticeable gelling. The scheme for synthetic route has been proposed.