离子液体[BMIm]NTf2中Ni纳米颗粒的制备及其催化性能研究

微波辐射下合成了1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺（[BMIm]NTf2）离子液体,并采用IR和1HNMR验证了其结构。利用化学还原法分别在水溶液和离子液体[BMIm]NTf2中制备了Ni纳米颗粒,采用XRD、TEM对其结构进行表征,并考察这两种纳米Ni颗粒在邻硝基苯催化加氢反应中的催化性能。结果表明,[BMIm]NTf2中制备的Ni纳米颗粒为面心立方结构,粒径在3—30nm。在还原过程中,离子液体同时起到了溶剂和修饰剂的作用,在所生成的M纳米颗粒的表面形成了一层离子液体的修饰层,阻止了Ni纳米粒子之间的团聚;在相同条件下,[BMIm]NTf2中制备的纳米Ni颗粒的催化活性显著高于常规水性介质中制备的Ni催化剂。     

离子液体[BMIm]NTf_2中Ni纳米颗粒的制备及其催化性能研究

微波辐射下合成了1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺([BMIm]NTf2)离子液体,并采用IR和1H NMR验证了其结构。利用化学还原法分别在水溶液和离子液体[BMIm]NTf2中制备了Ni纳米颗粒,采用XRD、TEM对其结构进行表征,并考察这两种纳米Ni颗粒在邻硝基苯催化加氢反应中的催化性能。结果表明,[BMIm]NTf2中制备的Ni纳米颗粒为面心立方结构,粒径在3～30 nm。在还原过程中,离子液体同时起到了溶剂和修饰剂的作用,在所生成的Ni纳米颗粒的表面形成了一层离子液体的修饰层,阻止了Ni纳米粒子之间的团聚;在相同条件下,[BMIm]NTf2中制备的纳米Ni颗粒的催化活性显著高于常规水性介质中制备的Ni催化剂。     

二氧化硅-磺酸催化制备生物柴油的研究

通过溶胶-凝胶法制备二氧化硅,进而与氯磺酸反应制得二氧化硅-磺酸(SiO2-SO3H)固体酸催化剂,用于大豆油与乙醇的酯交换反应制备生物柴油,考察了催化剂的处理温度、乙醇与大豆油的摩尔比、催化剂用量、原料油油酸含量和反应时间的影响.结果表明,二氧化硅-磺酸(SiO2-SO3H)具有较高的酯交换反应催化活性.制备生物柴油的最佳条件如下:催化剂处理温度为120℃、醇油摩尔比为6∶1、催化剂质量分数为5.0%(以大豆油计)、正庚烷的质量分数(以大豆油计)为30.0%、反应时间为6.0 h,此时生物柴油产率可达97.84%.与固体碱催化剂相比,固体酸催化剂对原料的酸度有更强的适应性.     

竹红菌素在DMF－H_2O混合体系中的电化学研究

本文研究了竹红菌素ＨＡ，ＨＢ以及１３－ＳＯ_３Ｎａ－ＤＤＨＡ在ＤＭＦ－Ｈ_２Ｏ（体积分数＝１）混合体系中的电化学氧化还原性质。结果表明，它们都为两步单电子还原过程，反应机理为：油溶性．水溶性１３－ＳＯ３Ｎａ－ＤＤＨＡ：（第一步）（质子化）；（第二步）．并且，ＨＡ，ＨＢ的单电子还原半醒自由基非常稳定，而１３－ＳＯ_３Ｎａ－ＤＤＨＡ单电子还原半醌自由基存在歧化反应，其速率常数ｋ_ｆ＝０．４０８。     

Bronsted-Lewis双酸性离子液体催化合成对苯二甲酸二(二乙二醇丁醚)酯

制备了具有不同SnCl2摩尔分数的Bronsted-Lewis双酸性离子液体3-(1-吡啶基)丙磺酸-氯化亚锡离子液体([3-(1-Py)-(CH2)3-SO3H]Cl-xSnCl2),x为Lewis所占的摩尔分数。用吡啶探针红外光谱作为表征手段,比较了不同x值催化剂的酸性强度变化,并将其应用于对苯二甲酸二(二乙二醇丁醚)酯的合成反应。考察了x值、原料配比、催化剂用量、带水剂用量、反应时间等因素对酯化率的影响,并对精制产品用1HNMR进行结构表征。结果表明,当x=0.5时,该离子液体的催化活性最高。以[3-(1-Py)-(CH2)3-SO3H]Cl-0.5SnCl2为催化剂,对苯二甲酸(PTA)和二乙二醇丁醚(DGBE)的摩尔配比n(DGBE):n(PTA)=2.3:1,催化剂用量为4.0%(PTA质量),带水剂正丁醚用量为60.0%(PTA质量),反应时间为2.5h,搅拌转速300r/min时,产品的酯化率高达99.43%。催化剂在不进行任何处理的情况下,可以循环使用5次。 关键词：双酸性离子液体;对苯二甲酸; 二乙二醇丁醚 ;对苯二甲酸二(二乙二醇丁醚)酯;增塑剂     

新型疏水性固体酸SBA-15-SO3H催化剂制备及其催化性能

采用水热法直接合成表面含丙磺酸基和不同烷基（如甲基、辛基和十六烷基）的疏水性介孔分子筛固体酸SBA-15-SO₃H。实验表明，固体酸的硫质量分数为3.53%～4.255%，酸含量为（0.84～1.08） mmol·g^-1，相对润湿接触角θ_{r(SBA-15-SO3H)}＜θ_{r(CH3-SBA-15-SO3H)}＜θ_{r(C8H17-SBA-15-SO3H)}＜θ_{r(C16H33-SBA-15-SO3H)}。催化剂对冰醋酸和正丁醇的酯化反应转化率可达75.5%，转化率随相对润湿角的增大而增大。     

磺酸基功能化磁性纳米粒子的制备、表征及除去水中Cu(Ⅱ)的研究

通过化学一步共沉淀法制备了疏水性的Fe3O4纳米粒子,然后采用反相微乳液法制备出分散性良好、粒径均匀的Fe3O4@SiO2复合磁性纳米粒子,紧接着用2-(4-氯磺酰苯基)乙基三甲氧基硅烷对其表面进行修饰,最终再经过1.0 MNaCl溶液处理得到富含磺酸基官能团磁性纳米吸附剂(Fe3O4@SiO2-SO3Na)。通过透射电镜(TEM)、X射线衍射(XRD)、红外光谱(FT-IR)、振动样品磁强计(VSM)等对其进行了表征,着重研究了其对水溶液中Cu(Ⅱ)离子的吸附性能。结果表明,溶液的pH值能显著影响吸附剂对Cu(Ⅱ)离子的吸附效果,其中pH值为5.1时吸附效果最佳,即Cu(Ⅱ)从初始的20mg.L-1降低至0.45mg.L-1,意味着97.8%的Cu(Ⅱ)从溶液中除去,通过用0.1M HCl洗涤可把Cu(Ⅱ)从吸附剂中脱离下来并且可以重复使用。     

AMPS多元聚合物水处理剂的研究进展

2-丙烯酰胺-2-甲基丙磺酸(AMPS)是一种丙烯酰胺类单体,由于分子中具有磺酸基团和不饱和乙烯双键,因此该聚合物具有良好的阻垢、分散等性能,与其它的单体共聚形成的多元聚合物在水处理剂中有良好的使用效果。本文对AMPS多元聚合物的特点及其在水处理方面的应用做一综述。     

碳酸二甲酯作酯化试剂催化合成水杨酸甲酯

报道使用一系列具有不同丙磺酸含量的SBA-15-SO3H分子筛为催化剂,考察了碳酸二甲酯作为酯化试剂与水杨酸发生反应制备水杨酸甲酯。结果表明,碳酸二甲酯是一种很好的酯化试剂,在一定的反应条件下,水杨酸的转化率和水杨酸甲酯的选择性可达到96.7%和57.7%。通过研究催化剂酸性对反应的影响,发现随着催化剂酸性增强和酸量增加,水杨酸的转化率和水杨酸甲酯的选择性也逐渐增高。     

A study on the effect of different chemical routes on functionalization of MWCNTs by various groups (-COOH, -SO3H, -PO3H2)

Pristine multiwall carbon nanotubes [MWCNTs] have been functionalized with various groups (-COOH, -SO3H, -PO3H2) using different single- and double-step chemical routes. Various chemical treatments were given to MWCNTs using hydrochloric, nitric, phosphoric, and sulphuric acids, followed by a microwave treatment. The effect of the various chemical treatments and the dispersion using a surfactant via ultrasonication on the functionalization of MWCNTs has been studied. The results obtained have been compared with pristine MWCNTs. Scanning electron microscopy, energy dispersive X-ray [EDX] spectroscopy, and transmission electron microscopy confirm the dispersion and functionalization of MWCNTs. Their extent of functionalization with -SO3H and -PO3H2 groups from the EDX spectra has been observed to be higher for the samples functionalized with a double-step chemical route and a single-step chemical route, respectively. The ID/IG ratio calculated from Raman data shows a maximum defect concentration for the sample functionalized with the single-step chemical treatment using nitric acid. The dispersion of MWCNTs with the surfactant, Triton X-100, via ultrasonication helps in their unbundling, but the extent of functionalization mainly depends on the chemical route followed for their treatment. The functionalized carbon nanotubes can be used in proton conducting membranes for fuel cells.     

Synthese und Struktur von Imino-bis[1]benzothiopyrano[4,3-b: 4,3-f] [1,5]dithiocinen

Synthesis and Structure of Imino-bis[1]benzothiopyrano[4,3-b:4,3-f][1,5]dithiocines Several substituted 3-Alkyl- respectively 3-Aryl-aminomethylene-2H-[1]benzothiopyran-4-thiones undergo a thermal reaction yielding the light yellow title compounds 2 . For the mechanism of this reaction we propose a condensation reaction of the starting compounds 1 loosing one molecule of amine in the first step followed by electrocyclisation reactions of the intermediates to products 2 . The structure of compounds 2 is elucidated by ¹H nmr spectroscopy and also x-ray analysis in case of compound 2b .     

改性聚环氧琥珀酸的合成及性能研究

以马来酸酐为原料,通过磺化、环氧化和开环聚合等一系列反应合成聚磺酸基环氧琥珀酸(PESSA),合成分子中引入-SO3H基团,通过IR和NMR进行了结构表征,实验表明PESSA具有优良的阻CaCO3、Ca3(PO4)2垢性能及稳定锌盐和分散氧化铁的性能.     

Synthetic potential of molluscan sulfatases for the library synthesis of regioselectively O-sulfonated D-galacto-sugars

The substrate specificities of three molluscan sulfatases (E.C. 3.1.6.1; snail, abalone, and limpet origins) were investigated with assorted p-nitrophenyl (pNP) di-O-sulfonated beta-D-galactopyranosides and beta-lactosides [3,6-SO(3) Gal (1), 3',6'-SO(3) Lac (2), 4, 6SO(3) Gal (3), 2,6-SO(3) Gal (4), 3,4-SO(3) Gal (5), and 3,6-SO(3) GalNAc (6); Ac, acetyl; Gal, galactose; Lac, lactose] together with mono-O-sulfonated beta-D-galactopyranoside [pNP 3SO(3)-Gal (7)] and tri-O-sulfonated alpha-D-galactopyranoside [2,3,6-SO(3)-alpha-Gal (11)]. Some notable differences between the substrate specificity of the three sulfatases were disclosed; snail sulfatase hydrolyzed the 3O- and 2O-sulfo groups of 1 and 4, respectively, to afford 6SO(3) Gal (9) in high yields, while the abalone enzyme did not act on 4. Only the limpet enzyme could cleave the 3O-sulfo groups of 7 to give pNP beta-galactoside. In contrast, every enzyme could utilize 11 as a good substrate to afford a mixture of 6SO(3)-alpha-Gal (13) and 2,6-SO(3) alpha-Gal (12). None of the enzymes could cleave the O-sulfo groups of 5 and 6, which indicates that a primary 6O-sulfo group tends to promote the enzymatic hydrolysis of O-sulfo groups at the secondary positions.     

Binary [Cu2O/MWCNT] and ternary [Cu2O/ZnO/MWCNT] nanocomposites: formation, characterization and catalytic performance in partial ethanol oxidation

Cuprous oxide agglomerates composed of 4-10 nm Cu2O nanoparticles were deposited on multiwalled carbon nanotubes (MWCNTs) and on ZnO/MWCNTs to give binary [Cu2O/MWCNT] and ternary [Cu2O/ZnO/MWCNT] composites. Di-aqua-bis[2-(methoxyimino)propanoato]copper Cu[O2CCCH3NOMe](2)·2H2O 1 in DMF was used as single source precursor for the deposition of nanoscaled Cu2O. The precursor decomposes either in air or under argon to yield CuO2 by in situ redox reaction. Thermogravimetric coupled mass spectroscopic analysis (TG-MS) of 1 revealed that methanol formed during the decomposition of 1 acts as a potential in situ reducing agent. Scanning electron microscopy (SEM) of the binary [Cu2O/MWCNT] nano-composite shows an increase of cuprous oxide loading depending on the precursor amount, along the periphery of the MWCNTs as well as formation of larger particle agglomerates. Transmission electron microscopy (TEM) of the sample shows crystalline domains of size 4-10 nm surrounded by an amorphous region within the larger particles. SEM and TEM of ternary [Cu2O/ZnO/MWCNT] clearly reveal that Cu2O nanoparticles are primarily deposited on ZnO rather than on MWCNTs. The catalytic activities of the [Cu2O/MWCNT] and [Cu2O/ZnO/MWCNT] binary and ternary composites were studied for the selective partial oxidation of ethanol to acetaldehyde with molecular oxygen. While using binary [Cu2O/MWCNT] (13.8 wt% Cu) as catalyst, acetaldehyde was obtained with a yield of 87% at 355 °C (selectivity 96% and conversion 91%). When nanoscale ZnO is present, the resulting [Cu2O/ZnO/MWCNT] composite shows preferential hydrogen and CO2 formation due to the fact that the dehydrogenation and total oxidation pathway is more favoured compared to the binary composite. Significant morphological changes of the catalyst during the catalytic process were observed.     

Long Chain Fatty Acid Uptake In Vivo: Comparison of [125I]-BMIPP and [3H]-Bromopalmitate

Insulin resistance is characterized by increased metabolic uptake of fatty acids. Accordingly, techniques to examine in vivo shifts in fatty acid metabolism are of value in both clinical and experimental settings. Partially metabolizable long chain fatty acid (LCFA) tracers have been recently developed and employed for this purpose: [9,10-(3)H]-(R)-2-bromopalmitate ([(3)H]-BROMO) and [(125)I]-15-(rho-iodophenyl)-3-R,S-methylpentadecanoic acid ([(125)I]-BMIPP). These analogues are taken up like native fatty acids, but once inside the cell do not directly enter beta-oxidation. Rather, they become trapped in the slower processes of omega and alpha-oxidation. Study aims were to (1) simultaneously assess and compare [(3)H]-BROMO and [(125)I]-BMIPP and (2) determine if tracer breakdown is affected by elevated metabolic demands. Catheters were implanted in a carotid artery and jugular vein of Sprague-Dawley rats. Following 5 days recovery, fasted animals (5 h) underwent a rest (n = 8) or exercise (n = 8) (0.6 mi/h) protocol. An instantaneous bolus containing both [(3)H]-BROMO and [(125)I]-BMIPP was administered to determine LCFA uptake. No significant difference between [(125)I]-BMIPP and [(3)H]-BROMO uptake was found in cardiac or skeletal muscle during rest or exercise. In liver, rates of uptake were more than doubled with [(3)H]-BROMO compared to [(125)I]-BMIPP. Analysis of tracer conversion by TLC demonstrated no difference at rest. Exercise resulted in greater metabolism and excretion of tracers with approximately 37% and approximately 53% of [(125)I]-BMIPP and [(3)H]-BROMO present in conversion products at 40 min. In conclusion, [(3)H]-BROMO and [(125)I]-BMIPP are indistinguishable for the determination of tissue kinetics at rest in skeletal and cardiac muscle. Exercise preferentially exacerbates the breakdown of [(3)H]-BROMO, making [(125)I]-BMIPP the analogue of choice for prolonged (>30 min) experimental protocols with elevated metabolic demands.     

Nano-CuFe2O4@SO3H Catalyzed Efficient One-Pot Cyclo-Dehydration of Dimedone and Synthesis of Chromeno[4,3-b]chromenes

Chlorosulfonic acid immobilized on CuFe₂O₄ nanoparticles (nano-CuFe₂O₄@SO₃H) was evaluated as a recoverable catalyst for the one-pot cyclo-dehydration of dimedone and synthesis of chromeno[4,3-b]chromene derivatives by reaction of arylaldehydes, dimedone or 1,3-cyclohexanedione, with 3-hydroxycoumarine or 4-hydroxycoumarine in good to excellent yield. Also, 2,2′-Arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) was synthesized by the reaction of aromatic aldehyde and dimedone using nano-CuFe₂O₄ in ethanol at room temperature. The catalyst could be recycled several times without significant loss of its catalytic activity. Clean methodologies, easy work-up procedure, high yield and simple preparation of the catalyst are some advantages of this procedure.     

SiO2-SO3H异相催化一步合成9-芳基-3,4,6,7,9,10-六氢吖啶-1,8(2H,5H)-二酮

以硅胶磺酸(SiO2-SO3H)为催化剂,4-芳硫基芳醛、1,3-环己二酮及醋酸铵为原料,于乙醇中合成了标题化合物.该方法具有处理方便、反应时间短、产率高、催化剂价廉易得、可回收重复使用等优点.     

固体超强酸La3+-SO42-/TiO2-Fe2O3催化合成对羟基苯甲酸丁酯

以固体超强酸La3+-SO42-/TiO2-Fe2O3为催化剂合成了对羟基苯甲酸丁酯,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产品收率的影响。试验结果表明:La3+-SO42-/TiO2-Fe2O3是合成对羟基苯甲酸丁酯的良好催化剂,当n(丁醇)/n(对羟基苯甲酸)=4.0,催化剂用量为对羟基苯甲酸质量的6%,反应温度120℃,反应时间4.0 h,对羟基苯甲酸丁酯的收率达到89.27%。     

8-氨基苯并[4,5]呋喃并[3,2-d]嘧啶类衍生物的合成与结构表征

以5-硝基水杨醛为原料,经过氰基化、醚化、两次成环、氯代等反应合成11个新型的8-位氨基取代苯并[4,5]呋喃并[3,2-d]嘧啶类化合物,利用1HNMR、13CNMR、IR和MS对其结构进行了表征,并对该反应条件进行了探索,得出最优的反应条件。     

碳基固体酸的制备及其应用

废纸浆经酸处理、碳化制得的碳基载体与浓硫酸磺化制得碳基固体酸催化剂。用FT IR、XRD、SEM、BET、酸碱滴定进行了表征,并考察碳基固体酸在合成二氧六环中的催化性能。结果表明废纸浆碳化为无定形碳,固体酸催化剂上-SO3H基含量可达2.3mmol/g,外形上仍保持纤维状结构。在反应温度170℃,反应时间为3h,二甘醇的转化率97%,二氧六环的选择性可达80%。