AuR2+-鲁米诺-K2S2O8化学发光体系与应用

研究了 8 羟基喹啉 (HR)与Au(Ⅲ )形成的配合物AuR+ 2 ,对K2 S2 O8氧化鲁米诺的增强作用 ,基于此建立了金的化学发光分析新方法 .以 8 羟基喹啉为配位体时 ,Au(Ⅲ )的检出限为 8× 10 -11μg/L ,工作曲线响应浓度范围在 1× 10 -9～ 1× 10 -7μg/L ,测定 1× 10 -7μg/LAu(Ⅲ )离子的RSD为 2 .0 % .配合物化学发光法检测硅酸盐单矿物晶格中痕量金可获得较好的分析结果     

用偶合反应流动注射化学发光法测定矿样和水样中的痕量铊

将Tl(Ⅲ)置换Co(Ⅱ)-EDTA配合物中的Co(Ⅱ)与Co(Ⅱ)-鲁米诺-H2O2化学发光体系相偶合,建立了流动注射化学发光测定铊的新方法。本方法测定铊的线性范围为3.0×10-6~1.0×10-2mg/mL,检出限为1.0×10-6mg/mL。对1.0×10-4mg/mL的Tl(Ⅲ)标准溶液连续11次测定的相对标准偏差为2.0%。方法可用于矿样和水样中铊的测定。     

水及血液中痕量铜的化学发光分析

本文采用自制仪器对鲁米诺-氰化钾-铜(Ⅱ)化学发光体系进行了系统研究,选定了测铜的最佳条件。该体系以铜(Ⅱ)作为氧化剂直接氧化鲁米诺产生λ_(max)为425nm的闪烁化学发光。测铜的线性范围为2×10~(-10)—6×10~(-7)/ml,检测下限为9×10~(-l2)g/ml,对10~(-10)g/ml铜(Ⅱ)测定的变异系数为4.6％。采用焦磷酸钠作为掩蔽剂可消除常见共存离子的干扰。此法用于水及人体全血中痕量铜的测定,结果均比较满意。     

流动注射-抑制化学发光测定多贝斯的方法研究

碱性条件下 ,多贝斯对铁氰化钾鲁米诺体系的化学发光有显著抑制作用 ,提出了一种用于多贝斯质量监测的流动注射 抑制化学发光分析方法。方法的线性范围为 1 .6× 1 0 - 5g/mL～ 2 .0× 1 0 - 7g/mL ;检测限 ( 3σ)为 4 4× 1 0 - 8g/mL ;RSD为 1 .5 % (c多贝斯=2 0× 1 0 - 7g/mL ,n =1 1 ) ;采样频率为 30 0次 /h。     

鲁米诺-AuCl4^- -H2O2体系化学发光反应的研究——-矿石中痕量金的测定

液相化学发光分析法是一种灵敏度很高的分析方法。有人曾用此法以测定痕量金,检测极限1×10~(-8)g/mL金,工作曲线的线性范围1×10~(-8)～1×10~(-7)g/mL金。本文首次提出并用自制液相化学发光分析仪(图1)研究了鲁米诺-AuCl_4~--H_2O_2液相化学发光体系,确定了用这一体系测定金的最佳条件,制定了测定的具体方法。检测极限4×10~(-11)g/mL金,工作曲线的线性范围1×10~(-10)～1×10~(-5)g/mL金,相对标准偏差     

Luminol-H_2O_2-Co(Ⅱ)体系化学发光反应的研究——水样、血液、矿石中痕量钴的测定

设计了液相化学发光分析仪.提高了检测钴的灵敏度,其检测下限为7.4×10~(-13)g/mL.线性范围扩大至1×10~(-11)～1×10~(-7)g/mL.首次用此法测定了全血和矿石中的痕量钴.为Seitz等的化学发光机理论点提供了新证据.     

流动注射化学发光法测定DL-酪氨酸

在甲醛存在下 ,高锰酸钾与DL 酪氨酸能够发生化学发光反应 ,产生很强的化学发光。据此采用流动注射技术 ,建立了一种测定DL 酪氨酸的化学发光分析法。方法的检出限为 2 .9× 1 0 - 8g/mL ,相对标准偏差为 1 .5 % ( 1 .0× 1 0 - 6g/mLDL 酪氨酸 ,n =1 1 ) ,线性范围为 1 .0× 1 0 - 7g/mL～ 5 .0× 1 0 - 6g/mL。     

高效液相色谱-化学发光法检测牛奶中磺胺类药物残留

以4种磺胺类药物(Sulfonamides, SAs), 即磺胺脒(Sulfaguanidine, SGD)、磺胺嘧啶(sulfadiazine, SDZ)、磺胺噻唑(sulfathiazole, STZ)和磺胺二甲嘧啶(Sulfamethazine,SMZ)为分析物,基于其在碱性介质中对Ag配合物-鲁米诺(Luminol)与Ni配合物鲁米诺两化学发光体系发光强度均具有抑制作用的性质,建立了高效液相色谱-化学发光法检测牛奶中4种磺胺类药物的方法.将化学发光体系作为高效液相色谱的新型检测器,并对两种化学发光体系的检测器性能进行了比较.4种磺胺药物经高效液相色谱分离后,分别与Ag-Luminol及Ni-Luminol化学发光体系作用.色谱条件为:反相C18分离柱(250 mm × 4.6 mm,5 μm);0.1%甲酸-甲醇为流动相(V/V);梯度洗脱;流速1 mL/min.化学发光条件:Ag、Ni-Luminol两体系中,Ag配合物浓度1.4×10.-4 mol/L(含0.12 mol/L NaOH);Ni配合物浓度1.5×10.-5 mol/L(含0.12 mol/L NaOH);Luminol浓度均为1.2×10.-7 mol/L;试剂流速均为1.0 mL/min.在最佳的分离检测条件下,Ag-Luminol体系检测4种磺胺类药物的检出限分别为0.15、0.96、1.10和1.50 μg/mL,加标回收率为81.0%~101.5%;Ni-Luminol体系检测SGD、SDZ、STZ 3种磺胺类药物的检出限分别为1.5、17.2和16.8 μg/mL,加标回收率为83.9%~110.8%.相比之下,Ag-Luminol体系作为高效液相色谱检测器更佳.应用本方法对牛奶中4种磺胺类药物残留量进行检测,结果令人满意.     

用偶合反应流动注射化学发光法测定铋

将Bi(Ⅲ)置换DTPA-Co(Ⅱ)配合物中Co(Ⅱ)与Co(Ⅱ)-Luminol-H2O2化学发光体系相偶合,建立了流动注射化学发光法测定铋的新方法.铋的线性范围为1.0×10-5～1.0×10-2mg@ml-1,对1.0×10-3mg@ml-1的Bi(Ⅲ)标准溶液连续11次测定的相对标准偏差为2.3%,检出限为4.0×10-6mg@ml-1.用于土壤样品中铋的测定,结果满意.     

流动注射化学发光抑制法测定痕量钒(Ⅴ)

基于钒 (Ⅴ )对罗丹明B 过氧乙酸 NaOH体系化学发光具有强烈的抑制作用 ,建立了流动注射化学发光测定痕量钒 (Ⅴ )的新方法。该方法线性范围为2 .0× 1 0 - 9～ 1 .0× 1 0 - 6g/mL ,检出限为 3.0× 1 0 - 1 0 g/mL ,对 1 .0× 1 0 - 7g/mL钒(Ⅴ ) 7次平行测定的相对标准偏差为 2 .0 %。已用于环境水样、钢样中钒 (Ⅴ )的测定 ,初步探讨了发光反应及其抑制机理     

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.