比值光谱导数法同时测定铝合金中铁,铜,锌

用比值光谱－导数分光光度法，在ｐＨ５．５缓冲溶液中，利用金属－２－（５－溴－２－吡啶偶氮）－５－二乙氨基酚（５－Ｂｒ－ＰＡＤＡＰ）－ＯＰ三元络合物显色体系，对混合物中铁，铜，锌三组分进行了同时测定。合成试样５次测定回收率在９７．３％－１０４．４％之间。应用于铝合金中铁，铜，锌的测定，各６次测定的ＲＳＤ分别为３．６６％，１．３８％，２．０３％。     

高碳铬铁中磷,硅,锰的电感耦合等离子体原子发射光谱测定方法的研究

采用过氧化钠在石墨坩埚中熔融分解样品，硝酸酸化后直接用ＩＣＰ测定。磷，硅，锰的测定范围分别为０．００５％－０．０７５％，０．３０％－６．００％，０．０３％－２．００％，相对标准偏差ＲＳＤ≤６．０％。     

电感耦合等离子体质变法测定高纯氧化铕中Cr,Mn,Co,Ni,Cu,Cd和Pb

报道敢用电感耦合等离子体质谱直接测定高纯氧化铕中Ｃｒ，Ｍｎ，Ｃｏ，Ｎｉ，Ｃｕ，Ｃｄ，Ｐｂ等杂质的方法，选择了仪器工作条件，讨论了谱干扰和基体效应。采用Ｒｈ作内标，减小了基体的影响。本法检出限为０．１２－２．２８μｇ／Ｌ，加标回收率为８８．６％－１０８．３％，相对标准偏差为３．２－７．９％，方法简便，快速。     

空气—C2H2火焰原子吸收光谱法测定中草药（鸦胆子,补骨脂）中…

用空气－Ｃ２Ｈ２火焰原子吸收光谱法测定了中草药中的Ｆｅ、Ｍｇ含量，讨论了测定条件，结果令人满意，方法的回收率：Ｆｅ９８．２０％－１０４．９％，ＣＶ１．０６％－１．０７％，Ｍｎ９９．４％－１０１％，ＣＶ＝０．５２％－１．９４％。     

中药片仔癀,六味地黄丸中的微量铬,铅和镉石墨炉原子吸收法测定

本文采用ＧＦ－ＡＡＳ加平台技术，基体改进剂，测定了中药片仔癀，六味地黄丸中铬、铅和镉的含量，铬、铅和镉的线性范围分别为０－０．８ｎｇ／ｍＬ，０－５０ｎｇ／ｍＬ，０－５ｎｇ／ｍＬ，回收率分别为１０２－１０３％，９９－１０１％，９７．５－９８％，本方法简便快速、准确。     

病人血样中痕量锗,锶的石墨炉原子吸收光谱法测定

本文运用石墨炉ＡＡＳ法加基体改进技术，测定了５０岁以上病人血清及环境水样中锗和锶的含量。用０．０１ｍｏｌ／ＬＨＮＯ３－０．１％ＴｒｉｔｏｎＸ－１００稀释血清，测定精度可与火焰法媲美。锗，锶的特征量分别为２８ｐｇ和１８ｐｇ；线性范围为０－２５０ｎｇ／ｍＬ和－３５．０ｎｇ／ｍＬ；相对标准偏差（ｎ＝１０）４．１０％和２．４９％；回收率分别为９２．２％－９９．０％和９２．０％１０２％。方法快速准确，结果满     

乙基磺原酸钾—MIBK萃取原子吸收测定重晶石中铅,镉

本文较详细地研究了以乙基磺原酸钾作为金属分离的溶剂萃取试剂测定重晶石中铅，镉的条件，并确定了测定方法，铅和镉与乙基磺原酸钾反应生成白色络合物，该络合物在水相溶液中能定量地萃入甲基异丁基甲酮中。它们的回收率分别为９７％－１０３％和９６％－１０１％。铅和镉分别在０－６μｇ／ｍＬ和０－０．８μｇ／ｍＬ呈线性关系。本法可测定０．０００ｘ％－０．ｘ％Ｐｂ，０．０００ｘ％－０．０ｘ％Ｃｄ．     

卡尔曼滤波在极谱分析中的应用——Sn（IV）,Pb（II）,In（III）,Cd（II）…

利用卡尔曼滤波（ＫＦ）技术，对互相干扰的Ｓｎ（Ⅳ），Ｐｂ（Ⅱ），Ｉｎ（Ⅲ），Ｃｄ（Ⅱ）体系进行了定量测试研究，在５．００×１０＾５～３．００×１０＾－４ｍｏｌ．Ｌ＾－１的浓度范围内，各组分测试的相对误差为－４．０％～３．８５％，对大理石抛光粉管理样中的Ｓｎ（Ⅳ），Ｐｂ（Ⅱ）进行了测定，结果与ＩＣＰ－ＡＥＳ结果表明，回收率在９５．０％～１０４％之间，为保证ＫＦ的精度，使用两个监控出口。数据说明效果良     

萃取色谱分离—原子发射光谱测定超高纯氧化铥,氧化镱和氧化镥中痕…

用２－乙基己基膦酸单２乙基己酯萃取色说分离－原子发射光谱测定超高纯Ｔｍ２Ｏ３，Ｙｂ２Ｏ３，Ｌｕ２Ｏ３中痕量稀土杂质，可用于纯度为９９．９９９９％－９９．９９９９９％Ｔｍ２Ｏ３，Ｙｂ２Ｏ３，ｌＵ２ｏ３的纯分分析，１４个稀土杂质的回收率在６７％－１３３％之间；相对标准偏差５．１％－２３．２％，分离周期１０－１３ｈ。     

偏最小二乘催化极谱法同时测定铂,钯,铑

应用Ｍ２７３Ａ电化学系统中的线性扫描技术，确定了０．７５ｍｏｌ／ＬＨ２ＳＯ４－１．５％ＮＨ４Ｃｌ－２．８ｍｍｏｌ／Ｌ（ＣＨ２）６Ｎ４－０．００２５％Ｎ２Ｈ４．Ｈ２ＳＯ４为偏最小二乘极谱法同时测定Ｐｔ、Ｐｄ、Ｒｈ的最佳极谱体系。Ｐｔ、Ｐｄ、Ｒｈ的线性范围为３．２ｍｇ／Ｌ、０－１５．０ｍｇ／Ｌ和０－１．０ｍｇ／Ｌ。模拟样品及实际样品的回收率在９０．３－１０７．７％之间。     

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.