新型分析试剂二(2-羟基-4-吡啶偶氮苯基)聚氧乙烯醚的性质

报道了一种新型聚合物二 (2 羟基 4 吡啶偶氮苯基 )聚氧乙烯醚 (di(2 hydroxyl 4 pyridineazobenzol)polyethenoxyether,PE·HPAB)的合成及性质 ,并与相应的小分子试剂 4 (2 吡啶偶氮 )间苯二酚 (PAR)比较。结果表明 :PAR进一步缩合为PE·HPAB后 ,性能明显改善 ,表现为 (1)在水和乙醇中溶解度显著提高 ,由PAR的微溶到PE·HPAB的易溶。对其表面张力的测定表明 ,PE·HPAB具有一定的表面活性。 (2 )与金属离子 (如Ni2 + )形成的络合物 ,在水溶液中稳定性增强 ,显色灵敏度提高了一倍。 (3)即使在大量非离子表面活性剂 (如吐温 80 )存在下 ,灵敏度也不降低 ,还有所提高。 (4)在表面活性剂析相萃取中 ,用PE·HPAB作萃取剂能明显改善分离效果 ,其一是在室温下就有很高的萃取率 ,而PAR和它的络合物即使在较高温度时也基本上不被萃取。其二是不象其它一些水溶性小分子 (如对甲酰基苯偶氮变色酸 )和高分子 (如聚乙烯醇缩对甲酰基苯偶氮变色酸 )等易受试剂的结构、物化性质、无机盐和表面活性剂浓度的影响 ,可用于微量甚至痕量组分的分离富集和测定。从而大大拓宽了表面活性剂析相萃取分离方法的应用范围     

聚乙烯醇缩对甲酰基苯偶氮变色酸的结构与性能

研究了聚乙烯醇缩对甲酰基苯偶氮变色酸(Polyvinylalcoholcondensedpoformylphenylazochromotropicacid,称PVA·FPAC)的结构与性能。结果表明,小分子试剂甲酰基苯偶氮变色酸(FPAC)高分子化后,性能有了较大的改善;表现为不同聚合度和羟基取代度(聚乙烯醇主链上羟基被取代的程度)的高分子显色剂其性能有较显著的差异;就聚乙烯醇缩对甲酰基苯偶氮变色酸而言,同一聚合度的试剂,羟基取代度越大,溶解性越好,显色反应的灵敏度越高,但对非有机溶剂液-固萃取影响不大;对不同聚合度的试剂,聚合度高的,显色灵敏度和萃取率均有明显提高。     

聚乙烯醇缩对甲酰基苯偶氮变色酸液—固萃取分离镉,铜,镍

研究了高分子显色剂聚乙烯醇缩对甲酰基苯偶氮变色酸作萃取剂时，Ｃｄ＾２＋，Ｃｕ＾２＋，Ｎｉ＾２＋的非有机溶剂液－固萃取行为，并与相应的小分子试剂对甲酰基苯偶氮变色酸作比较。结果表明，在吐温－８０－硫酸钠－水体系中ＰＶＡ．ＦＰＮＳ作萃取剂比ＦＰＮＳ更易获得高的萃取率和好的分离效果。     

低分子烃类对吐温80-盐-水液-固析相分离的影响

报导了环己烷、庚烷等的加溶对非离子表面活性剂（吐温－80）液－固析相分离的影响,使小分子显色剂对甲酰基偶氮变色酸（CApF)、偶氮胂1（ArsenazoI)和配合物在低温下就易从盐水溶液相富集到表面活性剂固相,萃取率达95％。并对不己烷、庚烃的加溶机理及温度的作用做了探讨。     

聚乙烯醇缩对甲酰基苯基偶氮变色酸萃取亲水蛋白质及其作用机理

探讨了高分子试剂聚乙烯醇缩对甲酰基苯基偶氮变色酸 (PV·FPNS)与牛血清蛋白 (BSA)和牛血红蛋白 (BHA)的相互作用 ,并依此采用浊点萃取法 (以Tween 80作为溶剂 )实现了上述两种蛋白质的定量萃取。研究了不同羟基取代度的高分子试剂对反应和萃取率的影响 ,并与相应的小分子试剂FPNS体系进行了比较。研究结果表明 :PV·FPNS与亲水蛋白质的相互作用主要靠静电力 ,且有高萃取率 ;FPNS与两种蛋白质也有类似的相互作用 ,但这种作用未能改善萃取效率 ;这进一步证明了靠静电作用生成一定结构的高分子化合物是提高萃取率的关键     

5,7-二磺酸基萘基重氮氨基偶氮苯与镉的显色反应及其应用

1　引　　言三氮烯类试剂是用于测定镉等过渡金属离子的有机显色剂。我们合成的 5 ,7 二磺酸基萘基重氮氨基偶氮苯(ＤＳＮＡＢ) ,由于共轭体系扩大和在萘环上引入两个 -ＳＯ3 Ｈ基 ,有利于在水相发色和测定 ,使灵敏度得到了很大的提高。实验结果表明 ,在ＴｒｉｔｏｎＸ 10 0为增敏剂 ,在硼砂 ＮａＯＨ介质中 ,试剂与镉显色反应的摩尔吸光系数可达 3.7× 10 5Ｌ·ｍｏｌ-1·ｃｍ-1,高于其它苯基重氮氨基偶氮苯类衍生物 ;在 1.2ｍｏｌ/Ｌ氨水介质中 ,摩尔吸光系数也可达 3.1× 10 5Ｌ·ｍｏｌ-1·ｃｍ-1,选择性也有改善。该显色剂已用于萃取…     

铂(Ⅳ)-溴酸钾-三氯偶氮氯膦褪色反应催化光度法测定微量铂

不对称变色酸双偶氮试剂是分光光度法测定稀土元素的灵敏显色剂,三氯偶氮氯膦[2-(4-K-2-膦酸基苯偶氮)-7-(2,4,6-三氯苯基偶氮)-1,8-二羟基-3,6-二磺酸萘]应用于催化光度法测定微量钌和铑已有报道,但用于铂的测定未见报道。实验发现,在酸性介质中Pt（Ⅳ)对溴酸钾氧化三氯偶氮氯膦的褪色反应有明显的催化作用。     

新显色剂偶氮胂DBF分光光度法测定稀土元素研究

变色酸双偶氮胂类化合物是光度法测定稀土元素的重要显色剂,如偶氮胂Ⅲ、三溴偶氮胂等。为研究各种取代基对这类显色剂与稀土配合物的影响,将对甲基二溴偶氮胂中的甲基换为甲酰基,合成得偶氮胂DBF,化学命名为2-(2-胂酸基苯偶氮)-7-(2,6二溴-4-甲酰基苯偶氮)-1,8-二羟基萘-3,6-二磺酸。     

3-对甲苯基-5-(2′-胂酸基苯偶氮)若丹宁光度法测定镍

合成了新型试剂3 对甲苯基 5 (2′ 胂酸基苯偶氮)若丹宁,研究了在表面活性剂存在下试剂与镍的显色反应,建立了光度法测定镍的新方法,其表观摩尔吸光系数为2.6×104L·mol-1·cm-1,镍量在0～20μg/10mL范围内符合比耳定律,可用于水及茶叶中镍的测定。     

SPAPT-CTMAB-AS显色反应的研究及应用

合成的新试剂1-(4-磺酸基苯基)-3-［4-(苯基偶氮)苯基］-三氮烯（SPAPT）与阳离子表面活性剂溴化十六烷基三甲铵（CTMAB）和阴离子表面活性剂（AS）在三乙醇胺调节的碱性（pH 11.00～11.20）介质中形成三元显色配合物。配合物最大吸收λ位于590 nm,测定阴离子表面活性剂十二烷基苯磺酸钠（DBOSO     

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.