无机盐含量及温度对微乳液体系相行为的影响

以脂肪醇聚氧乙烯醚(AEO-9)为表面活性剂,正丁醇、异丁醇及仲丁醇为助表面活性剂,正辛烷和柴油为油相,NaCl为无机盐,探究无机盐含量及温度对非离子型微乳液体系相行为的影响。结果表明,在正辛烷和柴油微乳液体系的盐度扫描实验中,各体系均发生WinsorⅠ→WinsorⅢ→WinsorⅡ型的变化,但柴油体系较正辛烷体系对无机盐的敏感性弱。随着AEO-9含量增加,中相微乳液体积增大,S₁(WinsorⅢ微乳液开始形成时需要的无机盐含量)增大,ΔS(维持WinsorⅢ微乳液所需的盐度范围)减小。在正辛烷和柴油微乳液体系的温度扫描实验中,其相行为及表面活性剂对中相微乳液增溶能力的影响与盐度扫描实验一致,且随表面活性剂含量增加,T₁(WinsorⅠ型向WinsorⅢ型转变时所对应的温度)增大,ΔT(维持WinsorⅢ型微乳液所需要的温度范围)减小。     

NPES/AOT反胶束增溶体系及性质研究

该文以壬基酚聚氧乙烯醚硫酸钠(NPES)与琥珀酸二(2-乙基己基)酯磺酸钠(AOT)复配体系为主表面活性剂,正丁醇为助表面活性剂,以柴油为油相,研究了反胶束增溶体系的粘度和电导率等物理化学性质;利用脉冲核磁共振图谱中水的T2弛豫时间分布曲线,研究了反胶束溶液中水的结合状态和分布,采用正规溶液理论计算了NPES/AOT的相互作用参数β值(-7.78),研究结果表明二者存在较强的协同效应,从理论上解释了二者在反胶束溶液中的最佳比例和协同增效作用.     

超增溶胶团自组装体原位合成纳米微粒

提出了一种原位合成纳米粒子的方法, 熔盐/超增溶胶团自组装法. 发现了熔盐的超增溶现象, 并提出了超增溶自组装机理. 在5%VB值小于1的表面活性剂和烃类组分形成连续相的反相胶束中超增溶自组装95%的熔盐, 熔盐形成多面体立方相, 并与表面活性剂的亲水基以静电吸附方式组装. 以超增溶胶团为纳米反应器, 熔盐与沉淀剂在胶团中进行原位合成. 该原位合成法具有不用水为溶剂、最大的沉淀量、粒子呈纳米级粒子和粒径分布范围窄等特点.     

柴油中相微乳液的制备和相图分析

制备了柴油/复合表面活性剂/正戊醇/MnCl2盐水五元微乳液;研究了MnCl2浓度、表面活性剂浓度及正戊醇浓度对五元微乳液体系中相微乳液的形成和鱼尾相图的影响.结果表明,用MnCl2扫描时形成的中相微乳液范围较窄;在鱼尾相图中,当复合表面活性剂D0821(双(C8-10烷基)二甲基氯化铵)和AEO-3(脂肪醇聚氧乙烯醚)的质量比为4∶6时,形成单相微乳液的表面活性剂效率最高,最佳表面活性剂的质量分数为8.3%.     

环境因素对正负表面活性剂体系相行为的影响

在1:1正负离子表面活性剂混合体系(十二烷基硫酸钠/辛基三甲基溴化铵 SDS-C8NM3Br; 十二烷基硫酸钠/十二烷基三甲基溴化铵,SDS-C12NM3Br)中加入短链脂肪醇 (乙醇,正丙醇,正丁醇),正负离子表面活性剂沉淀溶解,出现表面活性剂双水相.上相有液晶存在,下相有囊泡自发形成.折光率数据和电镜结果表明:上相为表面活性剂富集相,下相表面活性剂浓度较低.混合体系中,出现表面活性剂双水相所需短链脂肪醇的体积百分数,随短链脂肪醇的链长增加而降低.温度升高,出现表面活性剂双水相所需短链脂肪醇的体积百分数降低.对SDS/C8NM3Br/H2O体系的研究结果表明:超声处理,可使混合体系中沉淀向囊泡转化,与短链脂肪醇的加入后的作用类似.     

油酸钠微乳液体系的结构参数和电导行为研究

本文用稀释法测定了油酸钠/醇/正庚烷/水四组分W/O型微乳液体系的结构参数:水内核半径Rw,颗粒有效半径Re,界面层厚度L,平均聚集数N,颗粒总数Nd,分散相总界面积Ad等结构参数和醇从连续相转移到界面的自由能△Goc-i。结果表明微乳液水内核半径Rw大小在纳米尺度;随含水量的增加,水内核半径Rw直线增加,而醇转移的界面自由能-△Goc-i减小,在含水量较低时微乳液的稳定性较强。对助表面活性剂的种类、内水相盐度变化对油酸钠微乳液电导率的影响进行了考察,结果表明使用正丁醇时形成电导渗滤体系,而使用正戊醇、异戊醇和正己醇时形成的是非渗滤体系;内水相中加入Na NO3对电导渗滤有抑制作用。醇碳链长度增加及适当的盐度有利于微乳液体系的稳定。     

偶氮氯磷—mA—二苯胍—溴化十六烷基吡啶四元络合物光度法测定岩矿中微量铈组稀土

自发现表面活性剂具有“胶束增溶”作用、可大大提高多元络合物光度法的分析灵敏度后,表面活性剂用于多元络合物的光度测定便日趋增多。本实验较系统地研究和制定了以偶氮氯磷—mA(CPA—mA)为显色剂、二苯胍(DPG)为协同增色剂(第二配位体)、溴化十六烷基吡啶(CPB)为胶束增溶表面活性剂,在一定条件下与铈组     

无机盐强化烷基多苷清洗石油污染土壤的机理

研究了无机盐对一种烷基多苷(APG)产品APG1214物理化学性质的影响, 以期解释无机助剂对APG1214清洗老化石油污染土壤的强化作用. 实验发现无机助剂能够显著降低APG1214的临界胶束浓度(CMC)和浊点, 提高其表面活性, 对除油过程有促进作用. 利用动态光散射(DLS)和透射电镜(TEM)研究了无机助剂对APG1214聚集体流体力学半径(Rh)和形态的影响, 发现低浓度无机助剂可减小APG1214聚集体尺寸, 而高浓度助剂则增加聚集体尺寸. 研究结果显示出APG1214与常见非离子表面活性剂不同的特性. 洗油后溶液中表面活性剂聚集体的Rh分布明显变窄, 但平均半径有所增加; TEM观察显示, 洗油后溶液中囊泡壁明显变厚, 证明增溶是APG1214去除石油污染物的一条途径. 本实验得到的结论为APG1214在石油污染土壤修复方面的应用提供了依据, 并为在其他领域更好地利用这类绿色表面活性剂提供了参考.     

混合表面活性剂在非极性溶剂中的聚集行为

表面活性剂在非极性溶剂中的聚集行为比在水溶液中复杂得多. 水溶液中表面活性剂有一明确的临界胶束浓度(CMC),而在非极性溶剂中至今对CM C概念仍有怀疑^[1], 但已有多种手段如染料增溶法、水增溶法、光散射法、荧光偏振、紫外和核磁共振谱等证实并测定了非极性溶剂中 CMC 的存在^[1～5]. 表面活性剂在非极性溶剂中以非离子化状态存在, 其缔合主要靠两亲分子之间的偶极-偶极以及离子对相互作用, 那么在一种表面活性剂溶液中加入另一种表面活性剂, 即表面活性剂的复配, 必然对其聚集行为产生重大影响, 但迄今为止, 尚未见关于混合表面活性剂在非极性溶剂中聚集行为的报道. 本文采用碘光谱法和水增溶法测定了阴离子表面活性剂AOT 和非离子表面活性剂 Brij30 混合后在正庚烷中形成反胶束的 CMC, 以期考察表面活性剂的复配对其聚集行为的影响。     

凹凸棒土对戊醇异构体吸附分离性能的研究

采用十六烷基三甲基溴化铵和β-环糊精对凹凸棒土进行改性,研究了凹凸棒土对戊醇异构体的吸附行为。实验结果表明,相同条件下正戊醇在凹凸棒土上的吸附量大于2-甲基-丁醇。以环己烷为溶剂,十六烷基三甲基溴化铵改性后的凹凸棒土对戊醇异构体的吸附量较大,但吸附分离性能较差;而β-环糊精改性的凹凸棒土对戊醇异构体有较好的吸附分离性能,吸附选择性和分离因子分别为92.24和12.16。Langmuir方程拟合呈现出了良好的线性关系,戊醇异构体在凹凸棒土上的吸附等温线符合二级动力学方程模型。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.