Preparation of Pt-based catalyst by reverse microemulsion and its selective hydrogenation performance

采用反相（W/O）微乳液法制备负载型Pt基催化剂,以间氯硝基苯（m-CNB）选择加氢反应为探针,考察微乳液组成、助表面活性剂和油相种类、还原剂用量及载体种类等制备参数对催化剂活性的影响,并对Pt粒子及催化剂进行TEM表征。结果表明：选择十六烷基三甲基溴化胺（CTAB）/正丁醇/环己烷/H₂PtCl₆溶液的W/O微乳体系,m(CTAB)∶m(正丁醇)=3∶7,m(CTAB+正丁醇)∶m(环己烷)=3∶7,H₂PtCl₆溶液含量3.6%,N₂H₄·H₂O用量100 μL时制备的Pt/γ-Al₂O₃催化剂对m-CNB选择加氢活性最高。TEM分析表明催化剂中Pt粒子均匀分散在载体上。     

混合介质中羟乙基纤维素的阳离子化反应

在乙醇（Et.）和异丙醇（iPA）混合介质中,采用3-氯-2-羟丙基三甲基氯化铵（CTA）为醚化剂进行了羟乙基纤维素（HEC）的活化-阳离子化反应,对影响产物阳离子化取代度（Cds）和阳离子化效率（Cre）的因素进行了研究,并采用¹H NMR对产物的结构进行确认。结果表明,按m(HEC)∶m(Et.)∶m(iPA)∶m(25%NaOH)∶m(69%CTA)∶m(Ea)= 20∶20∶70∶13∶15∶8的配比,25 ℃时用胺碱活化30 min,60 ℃恒温反应4 h,产物的Cds为0.50,Cre达到75%。     

Zwitterionic polymer-coated porous poly(vinyl acetate–divinyl benzene)microsphere: A new support for enhanced performance of immobilized lipase

Enzyme immobilization has attracted great attention for improving the performance of enzymes in industrial applications. This work was designed to create a new support for Candida rugosa lipase(CRL) immobilization.A porous poly(vinyl acetate–divinyl benzene) microsphere coated by a zwitterionic polymer, poly(maleic anhydride-alt-1-octadecene) and N,N-dimethylethylenediamine derivative, was developed for CRL immobilization via hydrophobic binding. The catalytic activity, reaction kinetics, stabilities and reusability of the immobilized CRL were investigated. It demonstrated the success of the zwitterionic polymer coating and subsequent CRL immobilization on the porous microsphere. The immobilized lipase(p2-MS-CRL) reached27.6 mg·g~(-1) dry carrier and displayed a specific activity 1.5 times higher than free CRL. The increase of Vmax and decrease of Kmwere also observed, indicating the improvement of catalytic activity and enzyme-substrate affinity of the immobilized lipase. Besides, p2-MS-CRL exhibited significantly enhanced thermal stability and p H tolerance. The improved performance was considered due to the interfacial activation regulated by the hydrophobic interaction and stabilization effect arisen by the zwitterionic polymer coating. This study has thus proved the advantages of the zwitterionic polymer-coated porous carrier for lipase immobilization and its potential for further development in various enzyme immobilizations.     

微乳液法制备Pt/Al2O3催化剂及其催化氯代硝基苯选择加氢活性

采用十六烷基三甲基溴化铵（CTAB）/正丁醇/环己烷/H₂PtCl₆溶液的微乳体系,以N₂H₄·H₂O为还原剂,Al₂O₃为载体制备Pt/Al₂O₃催化剂。以邻氯硝基苯（o-CNB）选择加氢反应为探针,考察微乳液组成对Pt/Al₂O₃催化剂选择加氢活性的影响。运用XRD、XPS、IR、TEM和EDS对载体和催化剂进行表征。结果表明,微乳体系中CTAB∶正丁醇∶环己烷质量比9∶21∶70,3.6% H₂PtCl₆溶液中制备的Pt/Al₂O₃催化剂的o-CNB选择加氢活性最高。Pt粒子粒径5 nm左右,与载体之间没有明显的电子效应。对于取代位置不同的间、对氯硝基苯（m-CNB、p-CNB）加氢,Pt/Al₂O₃催化剂也表现出较高的催化活性。     

量子拓扑指数法预测多氯联苯醚的热力学性质

应用密度泛函理论(DFT),在B3LYP/6-31+G(d)基组上优化和振动分析计算了多氯联苯醚（PCDEs）所有209种可能的分子空间几何结构,得到其各原子之间空间拓扑距离,并建立拓扑空间距离矩阵。结合分子中各原子的支化度,应用原子的平衡电负性对分子图进行着色,得到量子拓扑指数PX₁、PX₂。采用多元线性回归技术建立联苯醚和209种可能结构的多氯联苯醚PCDEs 3种少见报道的热力学性质--标准生成热、标准生成自由能和相对自由能与PX₁、PX₂的定量关系拓扑模型,并用该模型分别对不同热力学性质进行预测与估算。结果表     

O,O-双十二酰化-三甲基壳聚糖季铵盐/胆固醇混合单分子膜性质

制备了O,O-双十二酰化-N,N,N-三甲基壳聚糖季铵盐（DATMC）,用FTIR、EA和¹H NMR对产物进行表征,并研究其与胆固醇（CH）的混合单分子膜性质。结果表明：DATMC在氯仿、THF和DMF中具有良好的溶解性。随着胆固醇含量的增加,DATMC /CH混合分子膜的崩溃压和极限分子占据面积均减小;在任何膜压下,体系的超额自由能ΔG_exc< 0,说明DATMC与CH二者处于混溶状态。并且X_CH=0.8时,ΔG_exc最小,此时相容性最好,体系最稳定。实验结果表明,调整胆固醇的含量可以改变混合单分子膜的性质。     

Research progress of diamondoids（Ⅰ）Structure and properties

金刚烃是由多个环己烷构成的饱和笼状烃,此类有机化合物的分子式为C_4n+6H_4n+12。金刚烷则是最小的金刚烃化合物（即n=1时）,其C原子骨架类似于金刚石的一个晶格单元。由于其独特的笼状结构和特殊的化学、物理和药理学性质,因此其逐渐成为研究的热点。本文介绍了金刚烃的结构、命名、性质,重点介绍了金刚烃的化学性质及其衍生物的合成。     

Synthesis and properties of α-methylacrylic acid high-carbon mixed esteras diesel pour point depressant

以α-甲基丙烯酸和马来酸酐为原料,经酯化反应合成了α-甲基丙烯酸高碳混合酯及马来酸酐高碳混合酯,确定了酯化反应条件。采用甲苯作溶剂,通过溶液聚合法合成了α-甲基丙烯酸高碳混合酯-马来酸酐高碳混合酯-乙酸乙烯酯-苯乙烯四元共聚物的柴油降凝剂,确定了最佳反应条件：单体配比1∶2∶3∶1,引发剂（偶氮二异丁腈）用量0.8%,反应温度为85 ℃,反应时间为6 h。考察了该降凝剂对锦州石化公司二套加氢柴油的降凝助滤效果,确定0.07%为降凝剂的最佳添加量。     

4-氯噻吩并[3,2-d]嘧啶的合成

报道了一条合成杂环4-氯噻吩并[3,2-d]嘧啶的新工艺。室温下2-氯丙烯腈缓慢滴加到巯基乙酸乙酯和乙醇钠的乙醇溶液中,经环合反应制得3-氨基噻吩-2-甲酸乙酯,其溶于乙酸乙酯后通入氯化氢成盐进行稳定和分离。3-氨基噻吩-2-甲酸乙酯的盐酸盐直接在过量的甲酰胺中,于140℃下第二次关环生成噻吩并[3,2-d]嘧啶-4（3H）-酮。噻吩并[3,2-d]嘧啶-4（3H）-酮在甲苯为溶剂,三乙胺为碱,100℃条件下与三氯氧磷进行氯代制备了4-氯噻吩并[3,2-d]嘧啶。本工艺与传统氯代方法进行比较后的优点是避免了使用过量有毒的三氯氧磷,后处理简单安全。     

含呋喃基双酚-双(4-羟基-3,5-二甲基苯基)呋喃甲烷的合成与表征

以2,6-二甲基苯酚和糠醛为原料,氢氧化钠为催化剂,经缩合反应合成了双（4羟基-3,5-二甲基苯基）呋喃甲烷。研究了各因素对反应收率的影响规律,选择反应温度、催化剂用量和反应时间为主要影响因素进行了正交实验。实验得出优化后反应条件为：n(2,6-二甲基苯酚)∶n(糠醛)=2.2∶1,n(2,6-二甲基苯酚)∶n(氢氧化钠)= 1∶0.11,反应温度为65?℃,反应时间为5?h。在较优条件下进行实验,所得产物收率为61.7%。采用FTIR、¹HNMR和MS表征确定了产物结构,并测得其熔点为151.1?℃,纯度为99.52%。     

Effects of Sr doping on high temperature electric properties of CaMnO3+δ - based compounds

Ca_1－xSr_xMnO₃（x=0,0.05,0.1）ceramic samples were prepared by using the sol-gel method and sintering in air with nitrales as starting materials. The phase composition,microstructure and electric properties of Sr doped samples were investigated. The results showed that the Ca_1－xSr_xMnO₃ ceramic samples was single phase and had condensed microstructure. Sr doped samples had better electric properties. The substitution of Sr for Ca had no significant effect on Seabeek coefficient but decreased its electrical resistivity,the highest power factor was 24.03×10^-5 W/（m·K²）at 600℃ for the sample of Ca_0.9Sr_0.1MnO₃.     

高速逆流色谱法分离纯化内吗啡肽-1

利用高速逆流色谱技术对化学酶法合成的内吗啡肽-1粗样进行分离。分析了内吗啡肽-1粗样杂质的分配系数,选择乙酸乙酯-甲醇-水（3∶1.5∶3,体积比）作为两相溶剂系统,上相为固定相,下相为流动相,在主机转速为900 r/min,流速为1.0 mL/min,检测波长为280 nm条件下分离制备。从120 mg粗样中分离得到71 mg样品,内吗啡肽-1的纯度达99.1%,样品回收率为91.5%。该方法简便、快速,为高纯度内吗啡肽-1少量制法提供了技术,并可为高速逆流分离小肽合成产物提供指导。     

Synthesis and characterization of ABn-type α-cyclodextrin monomer and its hyperbranched polymer

To obtain well-defined structures of α-cyclodextrin (α-CD) based monomer and its hyperbranehed polymer (HBP), a modified α-CD molecule with one electron-rich alkene and many electron-poor acrylates was first prepared through the esterification reaction between mono-ester undecylenic acid-α-CD and acrylic acid. It was then utilized as an AB_n-type monomer for subsequent ADMET polymerization between alkene and acrylate using the second generation Hoveyda-Grubbs catalyst in homogeneous water/organic [D₂O/(CD₃)₂CO] mixtures via acyclic diene metathesis (ADMET) polymerization. A novel cyclodextrin-based HBP was obtained in prolonged reaction time. The monomer and HBP were characterized by NMR, elemental analysis, FTIR, and MALDI-TOF MS measurements. It was found that the actual molecular structures of both monomer and polymer were identical with the designed structures. The produced polymers have molecular weights within 13.2 and 56.3 kDa, and their polydispersity indices range from 2.78 to 2.63 by multiangle laser light scattering-gel permeation chromatography. The degree of branching was determined by ¹H NMR spectroscopy and the values ranges from 0.41 to 0.52.     

Synthesis of Core/Shell Magnetic Porous Microspheres for Lipase Immobilization

Magnetic porous hydrophobic microspheres were prepared by modified suspension copolymerization of methacrylate (MMA) and divinylbenzene (DVB) in the presence of oleic acid coated magnetite (Fe₃O₄), and the microspheres were used as biocarrier for the lipase immobilization. The results showed that the magnetic microspheres possessed spherical shape, core/shell structure, porous structure and high magnetic content, and the size and structure of magnetic microspheres had no significant changes after enzyme binding. The particle average size of microspheres was 66 μm, the magnetic content of microspheres was up to 31%, and the magnetization saturation values of the core/shell magnetic microspheres were measured at 300 K to be 11.02 emu g⁻¹. Lipase was immobilized on the magnetic porous carrier at up to 16.30 mg/g carrier. Activity and enantioselectivity of the immobilized lipase for the synthesis of R-HMPC acetate were investigated, indicating an interfacial activation of the enzyme after immobilization. Moreover, the pH dependency and operational stability of the immobilized lipase were studied, and they possess high stability and can be reused for ten cycles with loss 10% activity.     

The chemical-enzymatic preparation and resolution of β-naphthyl alcohol

通过化学-酶相耦合的方法,成功制备出e.e.值>99%的S-β-萘乙醇,使其光学纯度达到了制备R-2-萘乙胺的要求。研究中以β-萘乙酮为原料,经硼氢化钠还原得到外消旋的β-萘乙醇。经过酶催化动力学拆分,β-萘乙醇中R型底物100%全转化为酯,S构型底物型被保留,这样体系中S构型底物的e.e.值达到近100%。本文还考察了若干因素对酶催化动力学拆分过程的影响,并最终确定了酶催化动力学拆分β-萘乙醇制备S-β-萘乙醇的最适条件：反应温度45 ℃,溶液为甲苯,底物浓度为100 mmol/L。     

超声条件下二异氰酸酯桥联改性β-环糊精

二异氰酸酯在超声条件下对β-环糊精（β-CD）进行改性,制得改性环糊精的交联聚合物。用正交试验法,以交联聚合物产率为评价指标,筛选二异氰酸酯改性环糊精主要影响因素和最佳合成工艺条件：n(异氰酸酯)∶n(β-CD) 的摩尔比约为1∶9;二异氰酸酯选用六亚甲基而异氰酸酯（HDI）,超声声强0.1 W/cm²,反应温度60℃,反应时间7 h。用红外光谱（IR）、扫描电镜（SEM）、热重分析（TG）等检测方法对交联产物进行表征。结果表明：改性后的β-CD保留了其原有的空腔结构,环糊精与二异氰酸酯反应生成了氨基甲酸酯基键,交联后的聚合物形成了具有网络的形貌;超声条件下合成环糊精聚合物可以降低反应温度、缩短反应时间,交联聚合物形成了微球状表面和多孔的空腔结构。     

Progress of asymmetric reduction with alcohol dehydrogenase for preparation of chiral alcohols

从醇脱氢酶在不对称还原制备手性醇化合物的应用出发,进行3个重要方面综述：酶分子——作为优质高效的生物催化剂,对红球菌属、乳酸菌属、赖氏菌属及嗜热微生物来源的天然或重组醇脱氢酶的催化作用进行探讨;辅酶的再生方法及优缺点分析——探索适合于特定催化反应的再生方法,以解决大规模应用时添加昂贵的辅酶带来的成本问题;体外进化技术——对目的酶活性、立体选择性与稳定性的提高。最终为酶催化制备医药及精细化工品中间体建立一条绿色高效经济的途径。     

(R)-邻氯扁桃酸的制备技术进展

(R)-邻氯扁桃酸是一种具有广泛用途的药物中间体和精细化工产品,主要用于抗血小板聚集药物氯吡格雷的合成,其制备方法主要包括不对称合成法和光学异构体拆分法。本文主要对(R)-邻氯扁桃酸的各种制备方法进行了介绍,并比较了不同制备技术的优缺点,最后对手性邻氯扁桃酸的催化合成前景进行了展望。     

一种新型炭载体在乙炔氢氯化反应中的应用

采用等体积浸渍法制备了一系列不同载体的HgCl₂催化剂,利用BET、原子荧光光谱仪（AFS）、元素分析仪（EA）等对样品进行了表征,考察了催化剂在固定床反应装置上进行乙炔氢氯化反应的性能,同时对催化剂失活原因进行了初探。结果表明,不同载体催化剂催化性能和失活原因差异很大,其中以AC-2（沥青基球形炭）为载体的HgCl₂/AC-2催化性能最佳,当HgCl₂含量为5%（质量分数）、乙炔空速36 h^－1、温度140 ℃、n(HCl)∶n(C₂H₂)=1.05～1.1时,其初始转化率>99%（比HgCl₂/AC-1提高39%）,选择性接近100%,寿命可达3168 h,催化性能优于现有工业高汞催化剂。     

Development of diamondoids（Ⅱ）preparation and applications

金刚烃是由多个环己烷构成的饱和笼状烃,此类有机化合物的分子式为C_4n+6H_4n+12。金刚烷则是最小的金刚烃化合物（即n=1时）,其C原子骨架类似于金刚石的一个晶格单元。本文对金刚烃类化合物的制备方法和应用前景进行了评述。迄今已公开的金刚烃制备方法包括化学合成法和从天然原油中分离提纯两种方法,化学合成法是目前这一领域的研究重点。由于其独特的笼状结构和特殊的化学、物理和药理学性质,金刚烃在医药、精细化学品、航空燃料、功能材料以及纳米技术等方面具有潜在应用前景。金刚烃化学有可能成为未来有机化学领域的重要分支学科。