含钒碳质页岩中钒的物相分析

将含钒碳质页岩经物相分离后 ,在浓度为 0 .75mol/ L H3 PO4介质中及 H2 O2 存在下 ,以 Na F、Cy DTA为掩蔽剂 ,5- Br- PADAP为显色剂 ,分别测定矿物各相中钒的含量。方法检出限为 2 .6× 1 0 -8mol/ L,RSD为4 .9% ( n=5)     

2-(2-喹啉偶氮)-4-甲基-1, 5-苯二酚测定银的研究

合成了新试剂2-(2-喹啉偶氮)-4-甲基-1,5-苯二酚(QAMDHB),研究了其与银的显色反应.在pH=4.7的乙酸-乙酸钠缓冲介质中,QAMDHB与银反应生成2∶1的稳定络合物,λmax=558 nm,ε=5.8×104 L*mol-1*cm-1,银含量在0～1.6 mg/L内符合比耳定律.方法用于环境废水中银含量的测定,结果满意.     

HPLC-MS法检测氟[18F]脱氧葡萄糖([18F]-FDG)注射液中2-氯-2-脱氧-D葡萄糖（ClDG）的含量

建立了[18F]-FDG注射液中杂质2-氯-2-脱氧-D葡萄糖(ClDG)含量的HPLC-MS测定方法。色谱柱为Alltima Amino 100A 5μ柱(250×4.6 mm),流动相为5 mmol/L乙酸铵-乙腈(10:90),柱温:35℃;流速:1 mL/min,进样量20μL。ClDG浓度在0.01～0.15 mg/mL范围内与峰面积有良好的线性关系,检出限为0.003 mg/mL,定量限为0.01 mg/mL。首次采用液质联用法检测[18F]-FDG注射液中杂质ClDG含量。     

一种二氮氧化喹恶啉化合物的分光光度法测定

用两种方法对 N,N′-二氧 -2 -甲基喹恶啉进行显色 :( 1 )在氢氧化钠介质中 ,在 70～ 80℃ ,N,N′-二氧 -2 -甲基喹恶啉水溶液产生异构化反应生成蓝色化合物 ,其浓度在 4.0～ 2 0 0× 1 0 - 3 mg/ m L范围符合比耳定律 ;( 2 )在亚硫酸氢钠 /浓硫酸介质中 ,在室温条件下 ,2 0～ 3 0 min后还原成淡黄绿到绿色化合物 ,在 1 0 .0～ 70 0× 1 0 - 3mg/ m L浓度范围符合比耳定律。此项研究为这类抗菌药物中间体提供了一种定量分析方法     

络合吸附波测定微量锑(Ⅲ)

在0.02 mol/LHAc-NaAc(pH 4.9)介质中,研究了Sb(Ⅲ)-7-(1-苯偶氮)-8-羟基喹啉-5-磺酸钠(BQ)体系电化学行为及其影响因素.Sb(Ⅲ)-BQ络合物在滴汞电极上于-0.58～-0.61 V间产生一良好的还原波,其一阶导数峰峰值I′p与Sb(Ⅲ)浓度在8.0×10-7～1.0×10-5mol/L范围内呈线性关系,检出限为4.5×10-7 mol/L.用该法测定冶金样品中痕量Sb(Ⅲ),取得了满意结果.对电极反应机理进行了探讨.     

新显色剂2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸光度法测定钒的研究

研究了新显色剂 2 -( 5-羧基 -1 ,3 ,4-三氮唑偶氮 ) -5-二乙氨基苯甲酸 ( CTZD-BA)与钒的显色反应的条件。在 p H 3 .0的 HAc-Na Ac介质中 ,CTZDBA与 V( )形成稳定的摩尔比为 2∶ 1的紫红色络合物 ,最大吸收波长在 583 nm处 ,表观摩尔吸光系数为 4.0 6× 1 0 4 L·mol- 1·cm- 1,V( )在 0～ 0 .8mg/L范围内遵守比耳定律。方法可不经分离直接测定铝合金样品中的钒 ,结果满意     

痕量 Ni(Ⅱ )的 4-(5-氯-2-吡啶偶氮 )-1,3-二氨基苯显色树脂相分光光度法测定

在 pH 9.0 碱性介质中, Ni(Ⅱ )定量地交换吸附在负载了 4-(5-氯-2-吡啶偶氮 )-1,3-二氨基苯的强酸性阳离子交换树脂上而显色, 可进行树脂相分光光度法测定痕量 Ni(Ⅱ ), 最大吸收波长λ max=535 nm, 表观摩尔吸光系数ε =1.2× 105 L@ mol-1@ cm-1, Ni(Ⅱ )量在 0～ 0.44 mg/L 范围内符合比尔定律, 用该法测定水样中痕量 Ni(Ⅱ ), 结果令人满意 .     

2-甲基-1-(4-芳基噻唑-2-基)-苯并咪唑-6-甲酸乙酯的合成、表征及生物活性

以4-乙酰氨基苯甲酸乙酯为原料设计合成了14 种2-甲基-1-(4-芳基噻唑-2-基)-苯并咪唑-6-甲酸乙酯新化合物. 化合物结构经质谱、1H NMR、红外光谱和元素分析等确证, 并用单晶X射线衍射仪测定了化合物5a的晶体结构. 生物活性实验结果表明, 化合物5c(500 mg/L)对小麦白粉病菌抑制率达到95%; 化合物5e对辣椒疫霉病菌(25 mg/L)的抑制率为61.9%, 对油菜菌核病菌(500 mg/L) 抑制率高达97.2%; 化合物5k(25 mg/L) 对小麦赤霉病菌抑制率为55.1%.     

4—氨基—三氮唑树脂对铬（Ⅵ）的吸附,机理及应用

4-氨基-三氮唑树脂(4-ATR)对Cr(Ⅵ)的吸附在pH=1时最佳,Cr~(3+)基本不被吸附。两者分离系数β_(CrVI/Cr~(3+)=5.52×10~3.静态饱和容量为179.4mg Cr(Ⅵ)/g树脂。用5mol/L HCl能还原洗脱。测得不同温度下的吸附速率常数k_(21·c)=1.59×10~(-3)S~(-1)、K_(25·c)=1.87×10~(-3)S~(-1)、K(30·c)=2.2×10~(-3)S~(-1);表观吸附活化能E_a=26.26kJ/mol;吸附热力学函数ΔH=6.16kJ/mol,ΔG~(298)=-15.1kJ/mol,ΔS~(298)=339.8J.mol·K.吸附机理表明4-ATR功能基上的N与Cr(Ⅵ)发生配位键合,配位摩尔比为1∶1.利用此树脂处理含Cr(Ⅵ)电镀废水,铬回收率可达95.7%。     

N,N-二甲基苯胺-对氨基二甲替苯胺氧化偶联反应催化分光光度法测定铬(Ⅵ)

在pH=3.2乙酸-乙酸钠缓冲介质中,研究了铬(Ⅵ)催化过氧化氢氧化对-氨基二甲替苯胺盐酸盐和N,N-二甲基苯胺的氧化偶联反应及其机理,建立了催化光度法测定痕量铬(Ⅵ)的新方法.该方法线性范围为0～0.12 mg/L;检出限为1.0×10-7 g/L;相对标准偏差为0.12%,直接用于水中铬(Ⅵ)的测定,结果满意.     

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.