ICP-MS 法测定高纯氧化铕中稀土杂质的研究

深入考察了ＩＣＰ－ＭＳ法测定高纯氧化铕时基体对稀土杂质测定的影响,研究了Ｐ５０７萃淋树脂分离大量基体Ｅｕ２Ｏ３的实验条件,建立了采用内标补偿直接测定大部分稀土杂质和经Ｐ５０７萃淋树脂分离基体后测定被干扰离子Ｔｍ相结合的高纯Ｅｕ２Ｏ３中稀土杂质的ＩＣＰ－ＭＳ分析方法。方法检出限为０．００５～０．０２１μｇ／Ｌ,加标回收率为８４％～１１２％。ＲＳＤ为１．４％～８．１％。本法适用于质量分数为９９．９９％～９９．９９９９％的高纯Ｅｕ２Ｏ３中稀土杂质的分析。     

感耦等离子体质谱法（ICP—MS）测定高纯氧化镝中痕量稀土杂质

本文报道用２－乙基己基膦酸单酯萃淋树脂为固定相，ＨＣｌ为淋洗液的萃取色谱法研究了高纯Ｄｙ２Ｏ３中的痕量稀土杂质和Ｄｙ２Ｏ３基体的分离条件，并用ＩＣＰ－ＭＳ法测定了高纯Ｄｙ２Ｏ３中的１４个稀土杂质，稀土元素的测定限为０．００１－０．００５ＩＣＰ－ＭＳ法测定了高纯Ｄｙ２Ｏ３     

化学分离－质谱法定量分析高纯Dy_2O_3中稀土杂质

以Ｐ_（５０７）萃淋树脂为固定相，ＨＣｌ－ＮＨ４Ｃｌ为淋洗液，研究了９９．９９９％～９９．９９９９％高纯Ｄｙ２Ｏ３中痕量稀土与基体Ｄｙ的分离法，以及火花源质谱法的测定条件。可分析９９．９９９９％超高纯Ｄｙ２Ｏ３中痕量稀土杂质，测定限０．００１～０．１×１０－６，误差３０％。     

高纯氧化铕中微量稀土杂质的化学光谱测定

将高纯Ｅｕ２Ｏ２通过Ｐ５０７萃淋树脂分离富集，分离掉大量基体Ｅｕ２Ｏ３剩下微量稀土杂质用碳粉吸附，加ＫＢＨ４作载体进行光谱测定，本方法可测定９９．９９９９％，纯度的Ｅｕ２Ｏ３中微量稀土杂质。     

化学光谱法测定5N氧化钆中14个稀土杂质元素

报道了化学光谱法测定５Ｎ高纯氧化钆中１４个稀土杂质元素，在Ｐ５０７萃淋树脂色层柱上分离氧化钆中稀土杂质元素，分别采用定量分离Ｌａ－Ｓｍ及Ｔｂ－Ｌｕ＋Ｙ和部份分离Ｅｕ的方法，并相应地采用碳粉吸附法和碳粉粉末法进行光谱测定。分离时间为３．５ｈ，测定下限为１．２μｇ／ｇ（ＲＥ）。     

化学分离—质谱法定量分析高纯Dy2O3中稀土杂质

以Ｐ５０７萃淋树脂为固定相，ＨＣｌ－ＮＨ４Ｃｌ为淋洗液，研究了９９．９９９％－９９．９９９９％高纯Ｄｙ２Ｏ３中痕量稀土与基本Ｄｙ的分离法，以及火花源谱法的测定条件。可分析９９．９９９９％超高纯Ｄｙ２Ｏ３中痕量稀土杂质，测定限０．００１－０．１×１０＾－６，误差３０％。     

等离子体质谱法测定高纯氧化铥中痕量稀土杂质元素的研究

本文提出了ＩＣＰ－ＭＳ内标补偿校正法直接测定５Ｎ－６高纯氧化铥中１４种痕量稀土杂质的方法，研究了ＩＰＣ－ＭＳ测定的谱干扰和基体效应。     

2—乙基己基膦酸单（2—乙基己基）酯萃淋树脂分离—火花源质谱法测定…

本文采用萃取色谱法以２－乙基己基膦酸单（２－乙基己基）酯（Ｐ５０７）萃淋树脂为固定相，以ＨＣｌ－ＮＨ４Ｃｌ体系为淋洗液，研究了９９．９９９％￣９９．９９９９％的高纯Ｙｂ２Ｏ３中稀土杂质和Ｙｂ基体的分离条件，将杂质淋洗液富集于复合螯合剂－活性碳上，经灼烧灰化后制成样品电极，进行质谱测定。测定下限达０．０１￣０．０５μｇ／ｇ，可用于高纯Ｙｂ２Ｏ３中杂质的测定。回收率在８０％以上。     

等离子体质谱(ICP-MS)测定高纯氧化镱中痕量稀土和非稀土杂质研究

本文报道ＩＣＰ－ＭＳ直接测定高纯（５Ｎ～６Ｎ）氧化镱中稀土和非稀土杂质的新方法．对ＩＣＰ－ＭＳ测定中的光谱干扰和基体效应进行了详细考察，结果表明：用镓作内标，可有效地补偿因氧化镱引起的基体效应．方法的检出限在０．０Ｘ－０．Ｘｎｇ／ｍＬ范围；相对标准偏差（ＲＳＤ）（ｎ＝７）＜１０％．已应用于高纯氧化镱的工艺流程及其产品分析．     

等离子体质谱（ICP—MS）测定高纯氧化镱中痕量稀土和非稀土杂质研究

本文报道ＩＣＰ－ＭＳ直接测定高纯（５Ｎ～６Ｎ）氧化镱中稀土和非稀土杂质的新方法，对ＩＣＰ－ＭＳ测定中的光谱干扰和基体效应进行了详细考察，结果表明，用镓作内标，可有效地补偿因氧化镱引起的基体效应，方法的检出限在０．０Ｘ－０．Ｘｎｇ／ｍＬ范围，相对标准偏差（ＲＳＤ）（ｎ＝７）〈１０％，已应用于高纯氧化镱的工艺流程及其产品分析。     

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.