β-环糊精-Cu(Ⅱ)配合物催化氧化邻苯二酚及其反应动力学

以β-环糊精(β-CD)作为骨架,经磺酰化反应、卤代反应和与L-组氨酸的亲核取代反应,得到了两种β-环糊精-组氨酸衍生物配体,再将配体与Cu(Ⅱ)配位,合成了具有多酚氧化酶催化活性的β-环糊精-Cu(Ⅱ)配合物。采用元素分析、傅里叶变换红外光谱、核磁共振波谱和原子吸收光谱等方法对配体和配合物的结构进行了表征。以O₂为氧化剂,用分光光度法测定了它们催化邻苯二酚氧化反应的性能,并考察了反应温度、pH值等因素对催化反应速率的影响。结果表明：β-环糊精-Cu(Ⅱ)配合物具有良好的催化性能;C-2位修饰得到的环糊精类金属衍生物因为活性基团与反应中心之间相对位置适宜,表现出较大的加速效果;反应动力学表明组胺基配位Cu(Ⅱ) 、β- CD疏水空腔和碱催化作用是反应加速的3个因素。     

Oxidation of α- and β-pinene catalyzed by MnIII (Salen) Cl·H2O

The cationic complex Mn^III (Salen) is a very effective catalyst for the oxidation of both- and-pinene. The higher selectivity towards epoxide formation supports the rebound oxygen mechanism. A turnover of 40 was obtained for both compounds after 16 h of reaction with a molar ratio 10.011 (feedstock: catalyst: iodosobenzene) and conversions between 50 and 60% were observed. A very high selectivity (55%) was determined for epoxide formation from -pinene. The good selectivity observed for myrtanal isomers (6.5 and 23.2%) from-pinene is related to the prior formation of the 1,2-epoxides.     

β-环糊精综合处理山苍子油的研究(二)

用β 环糊精与山苍子油进行包合反应,以提高柠檬醛含量。用正交实验考察了影响因素。结果表明:β 环糊精与山苍子油的配比是包合反应的最重要的影响因素,最佳反应条件为:β 环糊精的粒度为48μm,β 环糊精的含水量为14%左右,β 环糊精与山苍子油的配比为1.0g∶4.0ml,催化剂用量为0.2g,反应时间为90min。山苍子油产品含醛量可达83%。     

β-环糊精-丙磺酸催化合成14-烷基(芳基)-14H-二苯并[a,j]氧杂蒽衍生物

以β-环糊精(β-CD)为原料,在氢氧化钠水溶液中与1,3-丙磺酸内酯反应得到磺酸丙基醚-β-环糊精,再经阳离子交换树脂得到催化剂β-环糊精-丙磺酸(β-CD-PSA)。以苯甲醛和β-萘酚的缩合反应为模板反应,探讨反应温度、催化剂用量对反应的影响并优化工艺条件。以β-CD-PSA/H2O为催化体系,制备了一系列14-烷基(芳基)-14H-二苯并[a,j]氧杂蒽衍生物,β-CD-PSA用量为1%(摩尔分数),反应温度为100℃,反应时间为6~60 min,反应产率为85%~95%。催化剂具有良好的循环使用性能,至少循环使用10次,其催化活性未明显降低。     

苯基荧光酮-SDBS-β-CD-荧光猝灭法测定微量Mn(Ⅱ)

在pH7.4乙酸-乙酸钠介质中,有锰(Ⅱ)存在时,反应体系苯基荧光酮(PF)、β-环糊精(β-CD)及十二烷基苯磺酸钠(SDBS)所产生的荧光,由于锰(Ⅱ)与PF反应生成了配合物而产生猝灭现象,而且荧光强度的减弱程度与锰(Ⅱ)的质量浓度在0.12 mg/L以内呈线性关系。荧光检测体系在激发波长373 nm和发射波长534 nm条件下进行。基于上述事实,提出了测定微量锰的荧光猝灭法。应用此法测定自来水中的Mn(Ⅱ)的含量,结果令人满意。     

Zeolite P synthesis based on fly ash and its removal of Cu(Ⅱ) and Ni(Ⅱ) ions

Zeolite P was synthesized through hydrothermal method based on a kind of Class C fly ash(FA). X-ray diffraction(XRD), scanning electron microscopy(SEM), and Brunauer–Emmett–Teller(BET) were used to analyze and characterize the synthetic sample. The kinetics and thermodynamics of copper and nickel ions removed by the zeolite samples were experimentally explored in detail. The results of kinetic treatment showed the second-order exchange second-order saturation model(SESSM) can well describe the removal process of copper ions, while the first-order empirical kinetic model(FEKM) is the best kinetic model for nickel ions. Langmuir and Freundlich isotherms were used to fit the equilibrium concentration of Cu(Ⅱ) or Ni(Ⅱ) under certain conditions. Whether for copper or nickel ion, the Langmuir model is in good agreement with the experimental equilibrium concentration.The apparent theoretical removal capacities for Cu(Ⅱ) and Ni(Ⅱ) can reach to 138.1 mg·g~(-1) and 77.0 mg·g~(-1),respectively.     

分子尺度的复杂反应体系动力学模拟(Ⅱ) DCC-Ⅰ反应动力学模型的建立

以MonteCarlo模拟和结构导向集总相结合的方法对复杂反应体系DCC Ⅰ系统的反应动力学进行了模拟 ,建立了包括 75条反应规则的DCC Ⅰ的反应网络 .模拟结果表明各种产物的产率随反应深度的变化趋势是合理的 ,主要产物丙烯和汽油在最佳反应深度时的产率和产品性质能够很好地和标定数据拟合 ,建立的模型能够很好地反映出催化裂解的反应特性     

聚马来松香酰乙二胺-Cu(Ⅱ)配合物的合成及

介绍了聚马来松香酰乙二胺-Cu(Ⅱ)高分子配合物的制备和固定化香蕉多酚氧化酶的方法,测定了固定化香蕉多酚氧化酶的活性和米氏常数,研究了温度和pH值对固定化香蕉多酚氧化酶催化活性的影响及固定化香蕉多酚氧化酶的重复催化活性.结果表明,聚马来松香酰乙二胺-Cu(Ⅱ)高分子配合物,是香蕉多酚氧化酶的良好固定化载体,固定化香蕉多酚氧化酶的米氏常数Km=4.56×10-3 mol·L-1,小于天然香蕉多酚氧化酶的米氏常数(1.95×10-2mol·L-1),固定化香蕉多酚氧化酶的耐热性和耐酸碱性均优于天然香蕉多酚氧化酶,并有一定的重复使用性.对香蕉多酚氧化酶的固定化方式和固定化香蕉多酚氧化酶的催化反应机理也进行了初步探讨.     

Pd(Ⅱ)催化1,4-二苯基-1,3-丁二炔的合成

以苯乙炔为原料制备1,4-二苯基-1,3-丁二炔。以钯催化自偶联的方法合成对称性芳基丁二炔,通过优化碱、溶剂、反应时间和温度等条件得出最优反应条件。结果表明,采用最优条件,在2 mmol Ag NO3促进作用下,1,4-二苯基-1,3-丁二炔的产率达84.3%。     

Pd(Ⅱ)催化1,4-二苯基-1,3-丁二炔的合成

以苯乙炔为原料制备1,4-二苯基-1,3-丁二炔。以钯催化自偶联的方法合成对称性芳基丁二炔,通过优化碱、溶剂、反应时间和温度等条件得出最优反应条件。结果表明,采用最优条件,在2 mmol Ag NO3促进作用下,1,4-二苯基-1,3-丁二炔的产率达84.3%。     

A Simple and Highly Selective Biomimetic Oxidation of Alcohols with Hypervalent Iodine(III) Reagent Catalyzed by β-Cyclodextrin in Water

Abstract  

A simple, mild and highly efficient biomimetic oxidation of alcohols to the corresponding aldehydes or ketones with hypervalent iodine(III) reagent catalyzed by β-cyclodextrin was reported. β-cyclodextrin serves as a biological catalyst to enhance the reaction remarkably. The oxidation proceeded in water to afford aldehydes or ketones in excellent yields and high selectivity without remarkable over-oxidation to carboxylic acids. Selective oxidation of primary alcohols in the presence of secondary alcohols was also achieved. A possible mechanism for the oxidation was proposed.     

Synthesis of supramolecular biodendrimeric β-CD-(spacer-β-CD)21 via click reaction and evaluation of its application as anticancer drug delivery agent

The per-β-CD dendrimer (10), having 21 β-CD residues connected to the core β-CD in the primary and secondary sides with encapsulation efficacy and β-CDs moiety to preserve the biocompatibility properties was synthesized using click reaction. The dendritic network and β-CD cavity of the obtained dendrimer were utilized to form a supramolecular compound via the formation of a host-guest inclusion complex with methotrexate (MTX) drug molecule. The MTT assay of compound 10 showed very low toxicity on T47D cancer cells. In vitro drug release investigation at pHs 7.4, 5, and 3 indicated that the release manner was remarkably pH dependent.     

Mechanism and kinetics analysis of the phenol degradation by Fe(Ⅱ)-EDTA/K2S2O8 process

考察了Fe(Ⅱ)-EDTA/K2S2O8体系降解苯酚的影响因素,并对体系中苯酚的降解机理和反应动力学进行了初步分析。结果表明,铁离子、氧化剂形态以及紫外光辐照、螯合剂的存在对氧化体系作用效果影响显著。EDTA剂量为0.5 mmol/L、Fe(Ⅱ)剂量为1.0 mmol/L、K2S2O8剂量为2.0 mmol/L、溶液初始pH值为7.0、温度为60 ℃的条件下反应60 min,浓度为100 mg/L的苯酚降解率为71.48%,同样条件下紫外光辐照时降解率可达89.38%。降解机理与动力学分析表明,苯酚在Fe(Ⅱ)-EDTA/K2S2O8体系中降解途径以与Fe4+络合降解为主。     

一种新颖的脯胺酸衍生物与铜(Ⅱ)络合催化的不对称henry反应

一种新颖的脯胺酸衍生物-碳、碳对称的手性二胺配体与铜(Ⅱ)络合能够催化不对称的henry反应。在芳香族、脂肪族醛与硝甲烷的henry反应中,高产率的提供相应的β-硝基醇,其对应选择性能达到40-90%,并且反应能够在乙醇这种温和的条件下进行。重要的是,这个催化剂能够反复使用,在进行了5次循环实验后催化荆的活性没有明显降低,体现了其在绿色化学中的应用前景。     

L酸/B酸可调的磺酸功能化MIL-101(Cr)材料催化葡萄糖脱水 制备5-羟甲基糠醛

以九水合硝酸铬和单磺酸钠对苯二甲酸为原料,水为溶剂,采用水热法合成系列磺酸功能化MIL-101（Cr）,通过调节反应温度和时间,合成不同Lewis/Brönsted催化位点比例的磺酸功能化MIL-101（Cr）,采用PXRD、EDX、SEM、ICP-AAS及BET比表面积分析等技术对材料进行综合表征,并研究磺酸功能化MIL-101（Cr）催化葡萄糖脱水制备5-羟甲基糠醛的催化活性。催化反应动力学研究结果表明,MIL-101（Cr）-SO₃H中的Cr（Ⅲ）作为葡萄糖异构化反应的Lewis酸位点,－SO₃H作为果糖脱水反应的Brönsted酸催化位点,当催化剂的Brönsted酸和Lewis酸的摩尔比为1.1时,150℃下反应,5-羟甲基糠醛的选择性最高可以达到47.15%,5-羟甲基糠醛的产率最高达到46.0%。     

One-pot Synthesis of N-[Pheny1-(2-hydroxy-napthalen-1-y1) -methy1]-acetamide Catalyzed by SnCl4 · 5 H2O

采用SnCl4·5H2O为催化剂催化2-萘酚、苯甲醛和乙酰胺的三组分一锅法类Ritter反应合成了1-乙酰胺基苯甲基-2-萘酚(AAN).考察了原料配比、催化剂用量、反应温度和反应时间等因素对AAN收率的影响,确定了适宜反应条件为:n(2-萘酚)∶n(苯甲醛)∶n(乙酰胺)=1∶1.4∶1,催化剂用量为反应物总质量的6％、85℃反应35 min,AAN的收率可达96.2％.该合成工艺路线简捷,催化剂价廉易得,催化活性高,使用方便,反应条件温和,收率可观.     

The kinetic analysis of optimization and selective transportation of Cu(Ⅱ) ions with TNOA as carrier by MDLM system

This study covers the transportation of Cu(Ⅱ) ions by multi-dropped liquid membrane(MDLM) system and tri-noctylamine(TNOA) as carrier in kerosene. Batch experiments are held to obtain optimum conditions for the transportation of Cu(Ⅱ) ions such as volume of donor, organic, and acceptor phase 100 ml, p H of donor phase9.00, temperature 298.15 K, concentration of H_2SO_4 in acceptor phase 1.00 mol·L~(-1), concentration of TNOA in organic phase 5.00 × 10~(-3)mol·L~(-1)and rate of peristaltic pump 50 ml·min~(-1). Optimum circumstances of this extraction are as follows: p H of donor phase is 9.00, concentration of TNOA is 5.00 × 10~(-3)mol·L~(-1),1.00 mol·L~(-1)H_2SO_4 as acceptor phase, and flux rate is 50 ml·min~(-1). Cu(Ⅱ) ion transportation is consecutive first order irreversible reaction. Activation energy is found as 5.22 kcal·mol-1(21.82 k J·mol~(-1), this process is called as diffusion controlled system. Selective transportation of Cu(Ⅱ) ions with alkaline, alkaline earth, and different heavy metal ions at optimum conditions of single Cu(Ⅱ) extraction was conducted. According to the selective transportation Cu(Ⅱ) ions with alkaline and alkaline earth metal ions, Na~+, K~+, and Ba~(2+)ions are not detected in the acceptor phase, but 12.00% of Ca~(2+)ions is transported from donor phase to acceptor phase. At the end of the simultaneous extraction of Zn(Ⅱ), Fe(ⅡI), and Mo(VI) with Cu(Ⅱ) ions, 2.20% of Mo(VI), 0.80% of Fe(Ⅲ) and 3.60% of Zn(Ⅱ) are detected in the acceptor phase.     

Column adsorption of Cu(Ⅱ) by polymer-supported nano-iron oxides in the presence of sulfate: Experimental and mathematical modeling

Polymer-supported hydrous iron oxides (HFOs) are promising for heavy metals removal from aqueous systems.The ubiquitous inorganic ligands,e.g.,sulfate,are expected to exert considerable impacts on pollutants removal by these hybrid sorbents.Herein,we obtained a hybrid sorbent HFO-PS by encapsulating nanosized HFO into macroporous polystyrene (PS) resin.Both batch and column sorption experiments of Cu(Ⅱ) by HFO-PS were carried out in the presence of sulfate.Obviously,the presence of sulfate is favorable for Cu(Ⅱ) sorption onto HFO-PS.The performances of column Cu(Ⅱ) removal were fitted and predicted with Adams-Bohart,Clark,Thomas and BDST models.Thomas model is suggested best-fit to predict the breakthrough curves.Besides,a linear correlation is observed between breakthrough time and column length based on BDST model,which might be useful for predicting the breakthrough time for Cu(Ⅱ) removal by HFO-PS.     

活性炭负载[Rh(COD)Cl]2催化剂的制备及其催化性能

以氧化活性炭(OAC)为载体、自制[Rh(COD)Cl]_2为活性组分,制备了负载型催化剂[Rh(COD)Cl]_2/OAC(COD为1,5-环辛二烯),用XPS、N2吸-脱附、FTIR等对其结构进行了表征与分析,以β-蒎烯加氢反应为探针反应,考察了载体种类、氧化剂HNO3浓度、[Rh(COD)Cl]_2与OAC质量比对负载型催化剂[Rh(COD)Cl]_2/OAC性能的影响,在此基础上优化了β-蒎烯加氢工艺条件,并测定了催化剂([Rh(COD)Cl]_2/OAC)的重复使用性。结果表明,催化剂的最佳制备条件为:氧化活性炭为较佳载体,HNO3浓度为7.23mol/L,[Rh(COD)Cl]_2与OAC质量比为1∶8.3,此时β-蒎烯转化率均值为99.94%;顺式蒎烷选择性(以只生成蒎烷计,下同)均值为88.64%;顺式蒎烷收率均值为88.59%;β-蒎烯加氢工艺的最佳条件为:反应温度50℃,反应压力3.5 MPa,催化剂用量为β-蒎烯质量的3.5%,反应时间4.0 h,此条件下β-蒎烯转化率均值为99.88%;顺式蒎烷选择性均值为89.00%;顺式蒎烷收率均值为88.90%,[Rh(COD)Cl]_2/OAC催化剂在β-蒎烯加氢反应中表现出较佳的催化活性。催化剂重复使用4次后,β-蒎烯转化率仍可达89.64%,活性组分Rh的流失是造成催化剂失活的主要原因。     

Removal of Cd(Ⅱ) from dilute aqueous solutions by complexation–ultrafiltration using rotating disk membrane and the shear stability of PAA–Cd complex

Removal of cadmium(Ⅱ) ions from dilute aqueous solutions by complexation–ultrafiltration using rotating disk membrane was investigated. Polyacrylic acid sodium(PAAS) was used as complexation agent, as key factors of complexation, pH and the mass ratio of PAAS to Cd~(2+)(P/M) were studied, and the optimum complexation–ultrafiltration conditions were obtained. The effects of rotating speed(n) on the stability of PAA–Cd complex was studied with two kinds of rotating disk, disk Ⅰ(without vane) and disk Ⅱ(with six rectangular vanes) at a certain range of rotating speed. Both of the rejection could reach 99.7% when n was lower than 2370 r·min~(-1) and 1320 r·min~(-1), for disk I and disk Ⅱ, respectively. However, when rotating speed exceeds a certain value,the critical rotating speed(n_c), the rejection of Cd(Ⅱ) decreases greatly. The distribution of form of cadmium on the membrane was established by the membrane partition model, and the critical shear rate(γ_c), the smallest shear rate at which the PAA–Cd complex begins to dissociate, was calculated based on the membrane partition model and mass balance. The critical shear rates(γ_c) of PAA–Cd complex were 5.9 × 10~4 s~(-1), 1.01 × 10~5 s~(-1),and 1.31 × 10~5 s~(-1) at pH = 5.0, 5.5, and 6.0, respectively. In addition, the regeneration of PAAS was achieved by shear induced dissociation and ultrafiltration.