新显色剂2—（5—硝基—2—吡啶偶氮）—5—二甲所苯胺与钯显色反应的研究及其…

用新合成的偶氮试剂２－（５－硝基－２－吡啶偶氮）－５－二甲氨基苯胺研究了光度法测定钯的反应条件。结果表明，在０．４５－１．２ｍｏｌ／Ｌ盐酸介质中，钯与试剂形成稳定的蓝色配合物，其最大吸收波长位于６２１ｎｍ处，表观摩尔吸收系数为９．４×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，配合成的组成为Ｐｄ：５－ＮＯ２－ＰＡＤＭＡ＝１：２，钯浓度在０－１０μｇ／１０ｍＬ范围内符合比尔定律。本方法是目前测定钯的高灵敏     

2—[2‘—（4’—甲基—苯并噻唑）偶氮]—5—二甲氨基苯甲酸与钯（Ⅱ）显色反应…

合成了新试剂２－［２＇－（４＇－甲基－苯并噻唑）偶氮］－５－二甲氨基苯甲酸，并研究了其与钯（Ⅱ）的显色反应。实验表明，在５０％乙醇介质中，该试剂与钯（Ⅱ）反应生成１：１络合物，其最大吸收波长为６９８ｎｍ，表观摩尔吸光系数为５．８３×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１。     

新显色剂2－（5－硝基－2－吡啶偶氮）－5－二甲氨基苯胺与钯显色反应的研究及其应用

用新合成的偶氮试剂２－（５－硝基－２－吡啶偶氮）－５－二甲氨基苯胺（５－ＮＯ＿２－ＰＡＤＭＡ）研究了光度法测定他的反应条件。结果表明，在０．４５～１．２ｍｏｌ／Ｌ盐酸介质中，钯与试剂形成稳定的蓝色配合物，其最大吸收波长位于６２１ｎｍ处，表观摩尔吸收系数为９．４×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），配合成的组成为Ｐｄ：５－ＮＯ＿２－ＰＡＤＭＡ＝１：２，钯浓度在０～１０μｇ／１０ｍＬ范围内符合比尔定律。本方法是目前测定钯的高灵敏度和高选择性体系之一。用于含钯分子筛及二次合金管理样－８８中微量钯的测定，结果满意。     

葡萄糖脱氢酶微型生物传感器的研制及应用

以甲苯胺兰（ＴＢ）修饰碳糊微电极为基体，将葡萄糖脱氢酶（ＧＤＨ）用丝素蛋白膜固定于修饰微电极表面制成了生物传感器，在ｐＨ７．０的ＮａＯＨ－ＮａＨ２ＰＯ４缓冲溶液中，烟酰胺腺嘌呤二核苷酸（ＮＡＤ）的浓度为１．０４×１０＾－３ｍｏｌ／Ｌ的条件下，其响应电流与葡萄糖浓度在１．０×１０＾－４～３．２×１０＾－３ｍｏｌ／Ｌ范围内有良好线性关系，响应时间为２０ｓ；检测限为４．０×１０＾－５ｍｏｌ／Ｌ。该传感器     

新显色剂2—[2—（6—甲基—苯并噻唑）偶氮]—5—二甲氨基苯磺酸与钯（Ⅱ）…

合成了新试剂２－［２－（６－甲基－苯并噻唑）偶氮］－５－二氨基苯磺酸，并研究了其与钯（Ⅱ）的显色反应。实验表明，该试剂与钯（Ⅱ）反在生成１：１蓝色水溶性络合物，在阴离面活性剂十二烷基硫酸钠（ＳＤＳ）存在下可稳定２４ｈ，其最大吸收波长为６１５ｎｍ，表观摩尔吸光系数为７．９４×１０＾４．ｍｏｌ＾－＾１．ｃｍ＾－＾１。钯量在０－０．８μｇ／ｍｌ范围内符合比尔定律。本法是目前测定钯（Ⅱ）的高灵敏度显色反应     

2－（2－噻唑偶氮）－5－〔N，N－二羧基甲基）氨基〕苯甲酸与钯显色反应的研究及其应用

报道了一种对钯离子具有高灵敏度和选择性的新试剂２－（２－噻唑偶氮）－５－［（Ｎ，Ｎ－二羧基甲基）氨基］苯甲酸（ＴＡＤＣＡＢ）。在０．５ｍｏｌ／ＬＨＮＯ＿３介质中，ＴＡＤＣＡＢ与Ｐｄ（Ⅱ）形成蓝色配合物，组成为Ｐｄ：ＴＡＤＣＡＢ＝１：２，最大吸收波长６５２ｎｍ。钯浓度在０～１．４μｇ／ｍＬ范围内符合比耳定律。用双波长法测定，表观摩尔吸光系数ε＿（６５２．０～５３３．６）＝８．２×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），可以允许大量金属离子共存。所确立的方法无需掩蔽剂和其它分离手段，即可直接用于Ｐｔ－Ｐｄ催化剂中微量钯的测定，结果满意。     

5-Br-PADAB分光光度法测定钯

研究了４－（５－溴－２－吡啶偶氮）－１,３－二氨基苯（简称５－Ｂｒ－ＰＡＤＡＢ）分光光度法测定微量钯的反应,在乙酸介质中Ｐｄ（Ⅱ）与５－Ｂｒ－ＰＡＤＡＢ生成紫红色络合物,确定了分光光度法测定钯的新体系。在实验条件下试剂的最大吸收峰位于４３８ｎｍ处,络合物的最大吸收峰位于５６４ｎｍ处,表观摩尔吸光系数ε＝５．２０×１０－４Ｌ／ｍｏｌ．ｃｍ,用等摩尔连续变化法、摩尔比法测得络合比ｎ（Ｐｄ（Ⅱ））∶ｎ（５－Ｂｒ－ＰＡＤＡＢ）＝１∶１,钯离子的量浓度在４．２７×１０－８～１．５４×１０－５ｍｏｌ／Ｌ时,服从Ｂｅｅｒ定律。试验了３０种离子在一定量下不干扰测定。     

新试剂（MSBTAMB）双波长光度法测定微量铜（II）的研究

研究了新试剂２－〔２＇－（６＇－甲磺酰－苯并噻唑）偶氮〕－５－二甲氨基苯甲酸（ＭＳＢＴＡＭＢ）与铜（Ⅱ）的显色反应。试验表明，在ｐＨ２．０￣５．１和４０％乙醇介质中，Ｃｕ（Ⅱ）与ＭＳＢＴＡＭＢ形成１＋１稳定的配合物，其最大吸收波长为６４２ｎｍ，用单波长法测得配合物的Σ６４２＝６．７４×１０＾４Ｌ·ｍｏｌ＾－１·ｃｍ＾－１，双波长法测得的Σ６４２．５４６＝１．０９×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－     

新试剂二溴对硝基苯基重氮氨基—4—苯基—2—噻唑的合成及其与钯显色反应的研

报道了新试剂二溴对硝基苯基重氮氨基－４－苯基－２－噻唑的合成方法，并研究了在表面活性剂ＣＰＣ存在下，该试剂与钯（Ⅱ）的显色反应，结果表明，在ｐＨ６．４～７．８范围内，钯（Ⅱ）与该试剂可形成１：２灰紫色的配合物，其最大吸收波长位于６５０ｎｍ，表观摩尔吸光系数为７．０２×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１钯量在０～２２μｇ／２５ｍＬ，范围内符合比尔定律，该方法已用于Ｐｄ－Ｃ催化 微是钯的测定，结果满     

4,4‘—二偶氮苯重氮氨基苯与钴的显色反应研究及应用

研究了新试剂４,４＇－二偶氮苯重氮基苯（ＢＡＢＤＢ）与钴的显色反应。在ＴｒｉｔｏｎＸ－１００的存在下,ＰＨ９．５～１０．３的Ｎａ２Ｂ４Ｏ７－ＮａＯＨ缓总溶液中,钴与试剂形成１：２型鲜红色配合物,最大的吸收波长为５３５ｎｍ,表观摩尔吸光系数为１．４５是３３１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１。用拟定的方法测定了维生素Ｂ１２中钴含量,结果令人满意。     

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%.     

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.     

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.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.