铬（VI）与5—溴水杨基荧光酮的显色反应及应用

本文研究了Ｃｒ（Ⅵ）与５－溴水杨基荧光酮（５－Ｂｒ－ＳＡＦ）的显色反应。在ｐＨ６．０ＫＨ２ＰＯ４－ＮａＯＨ缓冲溶液中，Ｃｒ（Ⅵ）与５－Ｂｒ－ＳＡＦ、ＣＴＭＡＢ形式稳定的三元络合物，其最大吸收波长为５７２ｎｍ，表观摩尔吸光系数为１．４２×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。Ｃｒ（Ⅵ）浓度在０￣２．５μｇ／１０ｍＬ间服从比耳定律。用此法测定了环境水样中微量Ｃｒ（Ⅵ），获得满意结果。     

微乳液的增敏作用研究──Ni（Ⅱ）－5－Br－PADAP的分光光度法测定

以含水量８０％的阴离子型ＳＤＳ／ｎ－Ｃ＿（５）Ｈ＿（１１）ＯＨ／ｎ－Ｃ＿（７）Ｈ＿１６／Ｈ＿（２）Ｏ微乳液为介质，进行了Ｎｉ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ的分光光度研究，其表观摩尔吸光系数为１．１３×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），与相应含水量的ＳＤＳ胶束介质比较，测定的灵敏度显著提高（后者为７．５×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）），样品分析结果令人满意。     

二溴对甲基偶氮羧褪色光度法测定铬（Ⅵ）

研究了新显色剂二溴对甲基偶氮羧与Ｃｒ２Ｏ２－的褪色反应。发现它们在硝酸介质中具有高灵敏的褪色反应,Ｃｒ（Ⅵ）量在 ０～１６０μｇ／Ｌ内符合比耳定律．摩尔吸光系数为 １．２ ×１０ ５Ｌ·ｍｏｌ－１·ｃｍ－１。据此建立了一种新的测定Ｃｒ（Ⅵ）的光度法。     

铬（Ⅵ）与5－溴水杨基荧光酮的显色反应及应用

本文研究了Ｃｒ（Ⅳ）与５－溴水杨基荧光酮（５－Ｂｒ－ＳＡＦ）的显色反应。在ｐＨ６．０ＫＨ＿２ＰＯ＿４－ＮａＯＨｉＬ冲溶液中，Ｃｒ（Ⅳ）与５－Ｂｒ－ＳＡＦ、ＣＴＭＡＢ形式稳定的三元络合物，其最大吸收波长为５７２ｎｍ，表现摩尔吸光系数为１．４２×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。Ｃｒ（Ⅳ）浓度在０～２．５μｇ／１０ｍＬ间服从比耳定律。用此法测定了环境水样中微量Ｃｒ（Ⅳ），获得满意结果。     

用8－氨基喹啉高选择性分光光度法测定痕量锇的研究

研究了用８－氨基喹啉在ｐＨ３．６２的ＨＡｃ－ＮａＡｃ缓冲溶液中测定痕量Ｏｓ（Ⅳ）的分光光度法。常见的非贵金属和贵金属离子不干扰测定，并且选择性较好。Ｏｓ（Ⅳ）与８－氨基喹啉的组成比为１：３，表观摩尔吸光系数ε_（６００）＝１．３×１０~５Ｌ／ｍｏｌ·ｃｍ。在０～１０μｇ／１０ｍＬ范围内符合比耳定律。合成样品分析结果良好。     

5''''-硝基水杨基荧光酮分光光度测定微量碲

在ｐＨ４．１～４．６乙酸盐缓冲介质中，碲（Ⅳ）与５′－硝基水杨基荧光酮（５′－ＮＳＦ）、溴化十六烷基吡啶（ＣＰＢ）反应形成组成比为１∶４∶４的水溶性和稳定性皆佳的红色三元配合物，最大吸收波长为５４２ｎｍ，表观摩尔吸光系数为１．０２×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，桑德尔灵敏度是１．２５×１０－３μｇ·ｃｍ－２，线性范围为０～０．４０ｍｇ／Ｌ。据此提出了测定碲的灵敏、简便的分光光度分析新方法，直接用于测定硒粉中微量碲，结果较满意。     

CH（B~2Σ~－）和卤代甲烷、CS_2、O_2及Ar碰撞过程动力学研究

用四倍频ＹＡＧ激光（２６６ｎｍ）光解ＣＨＢｒ_３产生ＣＨ（Ｂ~２Σ~－）自由基，通过测量自发辐射ＣＨ（Ｂ→Ｘ）的时间分辨信号测得室温下ＣＨ（Ｂ）被卤代甲烷、ＣＳ_２、Ｏ_２及Ａｒ的猝灭速率常数（×１０~（－１０）ｃｍ~３·ｍｏｌｅｃ~（－１）·ｓ~（－１））分别为４．４±０．７（ＣＨ_２Ｃｌ_２）、５．２±０．４（ＣＨＣｌ_３）、５．０±０．７（ＣＣｌ_４）、８．２±０．３（ＣＨＢｒ_３）、７．９±０．７（ＣＳ_２）、０．１９±０．０２（Ｏ_２）及（１．１±０．１）×１０~（－２）（Ａｒ）．结果表明，除Ｏ_２外，其它猝灭剂对ＣＨ（Ｂ）的猝灭速率常数均大于对ＣＨ（Ａ）的。对卤代甲烷分子，猝灭速率常数显示了因Ｃｌ原子数增加而增加的趋势。     

β－CD对Zn（Ⅱ）－m－BrTPPS_4显色反应增敏作用的研究

本文系统研究了β－ＣＤ对Ｚｎ（Ⅲ）－ｍ－ＢｒＴＰＰＳ＿４显色体系的增敏作用，提出了高灵敏度测定痕量锌的分光光度新方法。显色体系的表观摩尔吸光系数为４．５７×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），Ｚｎ（Ⅱ）的浓度在０～５μｇ／２５ｍＬ符合比尔定律。应用本法于人发、铝合金等试样中锌的测定，回收率及方法对照结果令人满意。     

7-(1-苯偶氮)-8-羟基喹啉-5-磺酸-曲拉通X-100双波长分光光度法测定微量铟

研究了７－（１－苯偶氮）－８－羟基喹啉－５－磺酸与铟的显色反应及分析应用,在曲拉通Ｘ－１００存在下,于ｐＨ４．５的ＮａＡｃ－ＨＡｃ缓冲介质中,铟与题示试剂形成组成比为１∶３的黄色配合物,最大吸收波长为４４０ｎｍ,表观摩尔吸光系数为３．８６×１０４Ｌ·ｍｏｌ－１·ｃｍ－１,同时在５５０ｎｍ呈现负峰,用双峰双波长法测定铟的表观摩尔吸光系数为７．３３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１,灵敏度为单波长法的１．９倍,线性范围为０～０．６ｍｇ／Ｌ,该法用于硫硒化锌基陶瓷颜料及镀膜玻璃中铟的测定,结果满意。     

微乳液的增敏作用研究：Ni（Ⅱ）—5—Br—PADAP的分光光度法测定

以含水量８０％的阴离了了型ＳＤＳ／ｎ－Ｃ５Ｈ１１ＯＨ／ｎ－Ｃ７Ｈ１６／Ｈ２Ｏ微乳液为介质，进行了Ｎｉ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ分光光度研究，其表观摩尔吸光系数为１．１３×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，与相应含水量的ＳＤＳ胶束介质比较，测定灵敏度显著提高，样品分析令人满意。     

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.