用4,4‘—壬二酰基—双（1—苯基—3—甲基—吡唑酮—5）萃取分离钍

本文研究了标题试剂(简称H_2A)与Th(Ⅳ)的络合作用及萃取行为,考查了H_2A对Fe(Ⅲ)、Co(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)、Pb(Ⅱ)、Cu(Ⅱ)、La(Ⅲ)、Yb(Ⅲ)和U(Ⅵ)的萃取作用,试验了它对Th(Ⅳ)与上述元素及Ca(Ⅱ)、Mg(Ⅱ)、Cr(Ⅲ)、In(Ⅲ)、V(Ⅴ)、Zr(Ⅵ)的分离效果。     

混酸体系中31种金属离子的浮选行为

在总浓度为0.17～3.4N的HCl-HNO_3(〔HCl〕:〔HNO_3〕=2.4:1)体系中,以(18～60)×10~(-5)M的CPC为捕集剂,对(2.755～28.69)×10~(-5)M的31种金属离子进行了浮选,表明Ir(Ⅳ)、Pt(Ⅳ)、Ge(Ⅳ)、Sn(Ⅳ)、Bi(Ⅲ)、Au(Ⅲ)、T1(Ⅱ)、Pd(Ⅱ)、Sn(Ⅱ)可浮选95％以上,而Cr(Ⅵ)、Ti (Ⅳ)、Zr(Ⅳ)、Ga(Ⅲ)、In(Ⅲ)、Fe(Ⅲ)、Sb(Ⅲ)、Al(Ⅲ)、Mn(Ⅱ)、Fe(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)、Cd(Ⅱ)、Pb(Ⅱ)浮选率低于20％或几乎不浮选,Ru(Ⅱ)、Rh(Ⅱ)、Ir(Ⅱ)、Hg(Ⅱ)、Ag(Ⅰ)、TI(Ⅰ)部分被浮选。与HCl体系的浮选结果进行了比较,发现贵金属的浮选率和选择性在HCl-HNO_3体系中更好。进行了Au(Ⅲ)、Pt(Ⅳ)、Pd(Ⅱ)与Zn(Ⅱ)、Cd(Ⅱ)、Hg(Ⅱ)、Sb (Ⅲ)的分离试验,结果令人满意。     

离子色谱法同时检测水产品加工用水中10种阴离子

建立离子色谱法同时测定水产品企业加工用水中10种阴离子F-、ClO_(2)^(-)、BrO_(3)^(-)、Cl^(-)、ClO_(3)^(-)、NO_(2)^(-)、Br^(-)、NO_(3)^(-)、SO_(4)^(2-)和PO_(4)^(3-)。选用IonPac®AS19色谱柱(250 mm×4 mm),用KOH溶液梯度淋洗,以抑制电导检测器进行测定。10种阴离子在各自的质量浓度范围内与色谱峰面积呈良好的线性关系,相关系数均不小于0.9990,方法检出限为0.0005~0.005 mg/L。6次重复测定结果的相对标准偏差为0.95%~4.69%,样品加标回收率为80.0%~97.2%。该方法灵敏度高、简便、快速,适用于水产品企业加工用水中10种阴离子F^(-)、Cl^(-)、NO_(2)^(-)、Br^(-)、BrO_(3)^(-)、NO_(3)^(-)、SO_(4)^(2-)、PO_(4)^(3-)、ClO_(2)^(-)和ClO_(3)^(-)的检测。     

双水相萃取法分离铍(Ⅱ)、铁(Ⅲ)与铁(Ⅱ)、铬(Ⅲ)、锰(Ⅱ)、铝(Ⅲ)

研究了在聚乙二醇2000(PEG)-硫酸钠(Na2SO4)-邻苯二酚紫(PV)体系中铍(Ⅱ)、铁(Ⅲ)、铁(Ⅱ)、铝(Ⅲ)、铬(Ⅲ)、锰(Ⅱ)的萃取行为。试验结果表明,铍(Ⅱ)在pH 3.5-7.0及铁(Ⅲ)在pH 4.0-7.0范围内可以被PEG相几乎完全萃取,而铝(Ⅲ)、铬(Ⅲ)在pH 1.0-7.0、锰(Ⅱ)在pH 1.0-4.5、铁(Ⅱ)在pH 1.0-4.5则不被萃取。从而实现了将铍(Ⅱ)(pH 3.5)、铁(Ⅲ)(pH 5.0)与铝(Ⅲ)、铬(Ⅲ)、锰(Ⅱ)、铁(Ⅱ)混合离子的定量分离。同时探讨了PEG相的萃取机理。     

硫酸铵-锌试剂-Tween 80体系萃取分离铜(Ⅱ)、钴(Ⅱ)、镍(Ⅱ)、锌(Ⅱ)、镉(Ⅱ)、锰(Ⅱ)

研究了(H4)2SO4-Zincon(锌试剂)-Tween 80体系萃取分离金属离子Cu(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)、Cd(Ⅱ)、Mn(Ⅱ)的行为.试验表明,Cu(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)在pH 6～9范围内,与Zincon形成的螯合物可被Tween 80相完全萃取,而Zn(Ⅱ)、Cd(Ⅱ)、Mn(Ⅱ)基本不被萃取,进而实现了Cu(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)与Zn(Ⅱ)、Cd(Ⅱ)、Mn(Ⅱ)混合离子的定量萃取分离.     

微波消解-电感耦合等离子体质谱法测定血液中30种微量元素

建立了微波消解-电感耦合等离子体质谱法定量测定血液中微量元素的方法.采用微波消解进行样品前处理,在硝酸-双氧水混合体系中消解后稀释,电感耦合等离子体质谱法(ICP-MS)测定全血中铜(Cu)、铅(Pb)、锌(Zn)、银(Ag)、钡(Ba)、锡(Sn)、镍(Ni)、钴(Co)、钒(V)、锑(Sb)、铊(Tl)、汞(Hg)、锰(Mn)、钼(Mo)、硒(Se)、铬(Cr)、镉(Cd)、钍(Th)、钛(Ti)、铝(Al)、砷(As)、铁(Fe)、钙(Ca)、镓(Ga)、锶(Sr)、锂(Li)、镁(Mg)、铍(Be)、钠(Na)和钾(K)元素的含量.对样品前处理过程和仪器工作参数进行了优化,通过内标校正法降低基体效应.结果表明,上述元素相关系数R²均大于0.999 8,检测精密度为0.142%～12.856%.方法简单、准确、快速,可精确测定全血中多种微量元素的含量,为全血中元素含量的测定提供了高效可靠的分析手段.     

用聚乙二醇-硫酸铵-铬黑T体系从铁(Ⅲ)、钴(Ⅱ)、镍(Ⅱ)、铜(Ⅱ)中萃取分离镉的研究

本文研究了聚乙二醇(PEG)-(NH_4)_2SO_(4-)铬黑T(EBT)体系对Fe(Ⅲ)、CO(Ⅱ)Ni(Ⅱ)、Cu(Ⅱ)、Cd(Ⅱ)的非有机溶剂萃取行为.结果表明,在pH7~11的 NH_3·H_2O-NH_4Cl缓冲溶液中,Fe(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)可被聚乙二醇(PEG)相萃取,而Cd(Ⅱ)基本上不被萃取,从而获得了Cd(Ⅱ)与Fe(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)混合离子的定量分离.     

微波消解-电感耦合等离子体质谱(ICP-MS)法测定板栗中的矿物元素及稀土元素

为了准确测定板栗中矿物元素和稀土元素的含量水平,采用冷冻干燥方式预处理样品,选用硝酸和过氧化氢体系微波消解样品,结合电感耦合等离子体质谱技术,建立了板栗中钠(Na)、钾(K)、镁(Mg)、锰(Mn)、铁(Fe)、钒(V)、钴(Co)等19种矿物元素及镧(La)、铈(Ce)、镨(Pr)、钕(Nd)、钐(Sm)、铕(Eu)、钆(Gd)、铽(Tb)、镝(Dy)、钬(Ho)、铒(Er)、铥(Tm)、镱(Yb)、镥(Lu)、钇(Y)等15种稀土元素的同时分析测定方法。方法检出限为0.0027~0.78μg/L,相对标准偏差为1.4%~6.3%。通过国家标准物质GBW10019苹果的准确度实验验证,测定结果均在标准证书值范围内。实验结果表明,方法适用于板栗中矿物元素及稀土元素的同时测定。     

薄层色谱法测定痕量的镍(Ⅱ)、铜(Ⅱ)、镉(Ⅱ)、钴(Ⅱ)、锌(Ⅱ)的研究

在pH值为9.5～9.9的氨-氯化铵的缓冲溶液中,镍(Ⅱ)、铜(Ⅱ)、镉(Ⅱ)、钴(Ⅱ)、锌(Ⅱ)形成氨合络合物,而银(Ⅰ)、铋(Ⅲ)、铁(Ⅲ)、铁(Ⅱ)、汞(Ⅱ)、汞(Ⅰ)、锰(Ⅱ)、铅(Ⅱ)、锡(Ⅳ)、锡(Ⅱ)、钒(Ⅴ)、铝(Ⅲ)、钛(Ⅳ)等生成各种形式的沉淀。用甲醇-乙醇-氯化铵-氨-水体系(pH9.0～9.1),在硅胶H薄层板上,可以实现镍(Ⅱ)、铜(Ⅱ)、镉(Ⅱ)、钴(Ⅱ)、锌(Ⅱ)的分离。双硫腙显色后,用CS-930双波长薄层扫描仪测定含量。线性范围:锌0.01～0.20微克,铜0.01～0.25微克,镍、镉、钴0.01～0.30微克。     

气相色谱法一次进样分析氩、甲烷、一氧化碳、硫化氢、羰基硫、甲硫醇、一氧化二氮等15种组分

气相色谱法一次进样分析15个组分:氦(He)、氖(Ne)、氩(Ar)、氮(N_2)、甲烷(CH_4)、一氧化碳(CO)、乙烷(C_2H_6)、二氧化碳(CO_2)、硫化氢(H_2S)、羰老虢(COS)、六氟化硫(SF_6)、二氧化硫(SO_2)、甲硫醇(CH_4S)、乙硫醇(CH_3CH_2SH)、一氧化二氮(N_2O)、未知碳(U_(cc)).     

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%.     

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.     

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.     

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.