O／W微乳液对Zn（Ⅱ）—PAR的增敏作用

研究了十六烷基三甲基溴化铵９ＣＴＭＡＢ）／正戊醇／正庾烷／水组成的阳离子型Ｏ／Ｗ微乳液对以４－（２－吡啶偶氮）间苯二醇（ＰＡＲ）为显色剂，光度法测定锌的增敏作用。结果，方法简便、快速，与相应的胶束体系为介质比较，提高了测定灵敏度，结果可靠。通过对显色剂在水－微乳液和在水－胶束相中分配系数的测定，初步了微乳液的增敏作用机理。     

阳离子型微乳液对显色剂1—（2—吡啶偶氮）—2—萘酚的增溶作用

以光度法研究了阳离子型微乳液对显色剂１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）的增溶作用，通过测定ＰＡＮ在阳离子型ＣＴＭＡＢ／ｎ－Ｃ５Ｈ１１ＯＨ／ｎ－Ｃ９Ｈ２０微乳液中的“胶束位”ｎ和结合常数Ｋ，并与相同表面活性剂胶束体系比较，探讨了微乳液对显色剂ＰＡＮ的增溶作用。     

混合微乳液的增敏作用研究：Cd（Ⅱ）—5—Br—PADAP的分光光度测定

研究了在Ｏ／Ｗ混合微乳液ＳＤＳ－ＯＰ／ｎＣ４Ｈ９ＯＨ／ｎ－Ｃ７Ｈ１６／Ｈ２Ｏ介质中，Ｃｄ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ的显色反应。结果表明显色反应的灵敏度较单一的ＳＤＳ微乳液，单一的ＯＰ的微乳液，混合ＳＤＳ－ＯＰ胶束的介质中，具有更好的增敏作用和稳定性，Ｃｄ浓度在０－５μｇ／１００ｍＬ范围内符合比尔定律。方法用于废水和环境水样中微量Ｃｄ的测定，结果满意。     

微乳液的增敏作用研究—5—Br—PADAP分光光度测定锰（Ⅱ）

以含水量８０％的Ｏ／Ｗ型ＳＤＳ／正丁醇／正庚烷／水微乳液为介质，以５－Ｂｒ－ＰＡＤＡＰ为显色剂，分光光度测定Ｍｎ（Ⅱ）。表观摩尔吸光系数ε５７０－１．０８×１０＾ｄ５Ｌ．ｍｏｌ＾－ｄ１．ｃｍ＾－１，与相同含水量的ＳＤＳ胶束体系相比，测定灵敏度有显著提高，改善了实验条件。方法用于铝合金和茶叶中Ｍｎ（Ⅱ）的测定，结果令人满意。     

微乳液的增敏作用研究：Ni（Ⅱ）—5—Br—PADAP的分光光度法测定

以含水量８０％的阴离了了型ＳＤＳ／ｎ－Ｃ５Ｈ１１ＯＨ／ｎ－Ｃ７Ｈ１６／Ｈ２Ｏ微乳液为介质，进行了Ｎｉ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ分光光度研究，其表观摩尔吸光系数为１．１３×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，与相应含水量的ＳＤＳ胶束介质比较，测定灵敏度显著提高，样品分析令人满意。     

非离子型微乳液的增敏作用研究——Cd（Ⅱ）—5—Br—PADAP吸光光 …

在含水量９０％的非离子型微乳液－－乳化剂ＯＰ／正丁醇／正庚烷／水中,以５－Ｂｒ－ＰＡＤＡＰ为显色剂,吸光光度法测定镉,结果表明,络合物的λｍａｘ为５６５ｎｍ,摩尔吸光系数这２．１４×１０＾５Ｌ·ｍｏｌ＾－１ｃｍ＾－１,与相同含水量的乳化剂ＯＰ胶束体系相比,测定灵敏度明显提高,试验条件有所改善,镉含量在０－８．０μｇ／１０ｍｌ范围符合比耳定律。     

微乳液介质—1—（2—吡啶偶氮）—2—萘酚光度法测定汽油中环烷酸铁的含量

本研究了微乳液为介质时，铁与１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）的显色反应。选择７３０ｎｍ处为测定波长，ε为１．４×１０＾４Ｌ．ｍｏｌ＾－＾１．ｃｍ＾－＾１，铁量在０－５０μｇ／２５ｍｌ范围内符合比耳定律，该法适用于汽油中环烷酸铁的测定。     

微乳液对显色剂1—（2—吡啶偶氮）—2—萘酚的增溶作用

１引言与胶束同属分子有序排列的微乳液具有超低界面张力和更高的增溶量，我们曾在国内外首次研究了合适的微乳液介质对光度分析具有较好的增敏作用，及讨论了其增溶、增敏作用的机理。本文利用光度法研究了微乳液对显色剂１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）的增溶作用。２实验部分２．ｌ仪器ＵＶ－２４０分光光度计（日本岛津）。２．２试验方法准确移取适量ＰＡＮ溶液于数只２５ｍＬ容量瓶中，依次加入不同量的微乳液原液或胶束溶液及５ｍＬ缓冲溶液，以相应的试剂空白，测绘一定波长范围内的吸收光谱。３结果与讨论３．１微乳液介…     

微乳液的增敏作用研究—5－Br－PADAP分光光度测定锰（Ⅱ）

以含水量８０％的Ｏ／Ｗ型ＳＤＳ／正丁醇／正庚烷／水微乳液为介质，以５－Ｂｒ－ＰＡＤＡＰ为显色剂，分光光度测定Ｍｎ（Ⅱ）．表观摩尔吸光系数ε５７０＝１．０８×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，与相同含水量的ＳＤＳ胶束体系相比，测定灵敏度有显著提高，改善了实验条件．方法用于铝合金和茶叶中Ｍｎ（Ⅱ）的测定，结果令人满意     

二烷基磷（膦）酸钠盐萃取体系的相行为

用二烷基磷（膦）酸钠盐ＮａＡ作为阴离子表面活性剂，测定了ＮａＡ－醇－油－水体系Ｗ／Ｏ型微乳液中水的增溶量，用类三元相 图单相微乳区，测定了ＮａＤＴＭＰＰ－ＨＤＴＭＰＰ－煤油－水（含Ｎａ２ＳＯ４）体系相的变化，并讨论了溶剂、醇、温度、含盐量等对相行为的影响。     

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%.     

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.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.