水杨醛缩-5-碘-8-氨基喹啉的合成及荧光光度法测定煤渣中痕量镓的研究

报道了新息夫碱试剂水杨醛缩－５－碘－８－氨基喹啉（ＳＡＩＡＱ）的合成。用元素分析、红外光谱法确定了其结构。测定了ＳＡＩＡＱ的酸度常数Ｋａ１＝２．４０×１０－４，Ｋａ２＝２．９８×１０－９。在ｐＨ３．５０～５．００范围内ＳＡＩＡＱ与Ｇａ３＋形成稳定的荧光螯合物，且在λｅｘ／λｅｍ＝４２８ｎｍ／５４０ｎｍ产生强烈荧光。其荧光强度与Ｇａ３＋的浓度在１．５μｇ／Ｌ～２６０μｇ／Ｌ范围内呈线性关系，检出限１．５μｇ／Ｌ，考察了共存离子的影响，选择性高。已应用于煤渣中痕量镓的分析。     

用新试剂2[—5‘—氟—2’—砷酸基苯）偶氮]—1,8—二羟基—3,6—萘二磺酸荧光法

研究了试剂２－」５’－氟－２’－－砷酸基苯）偶氮「－１，８－二羟基－３，６－萘二磺酸与硼的荧光性能。硼与试剂形成１：２的强荧光配合物，其λｅｘ／λｅｍ＝２３４ｎｍ／３８０ｎｍ，Ｂ（Ⅲ）含量在０－３６０μｇ／Ｌ范围内呈良好线性关系，检测限为２．０６μｇ／Ｌ，据此建立了测定微量硼的新方法。     

用新试剂2-[(5’-氟-2’-砷酸基苯)偶氮]-1,8-二羟基-3,6-萘二磺酸荧光法测定硼

研究了试剂２－［（５’－氟２’－砷酸基苯）偶氮］－１，８－二羟基－３，６－萘二磺酸与硼的荧光性能．硼与试剂形成１：２的强荧光配合物，其λｅｘ／λｅｍ＝２３４ ｎｍ／３８０ ｎｍ， Ｂ（Ⅱ）含量在 ０～３６０μｇ／Ｌ范围内呈良好线性关系，检测限为２．０６μｇ／Ｌ，据此建立了测定微量硼的新方法。该方法应用于茶叶、铝合金及粮食等样品中微量硼的测定，结果满意．     

用新荧光试剂7—（2,4—二羟基—5—羧基苯偶氮）—8—羟基喹啉—5—磺酸？…

研究了新荧光试剂７－（２，４－二羟基－５－羧基苯偶氮）－８－羟基喹啉－５－磺酸（ＤＨＣＢＡＱＳ）与镁形成配合物的荧光性能，在ｐＨ９．０的硼砂缓冲介质中，试剂与镁形成１：１配合物，其λｅｘ／λｃｍ＝３５８ｎｍ／５０２ｎｍ。镁（Ⅱ）含量在０￣４８０μｇ／Ｌ范围内呈良好线性关系，检测限为３．７μｇ／Ｌ，据此建立测定痕量镁的新方法，并应用于矿样及血清中痕量镁（Ⅱ）的测定，结果满意。     

水杨醛缩—5—碘—5—氨基喹啉的合成及荧光光度法测定煤渣中痕量镓的研究

报道了新息夫碱试剂水杨醛缩－５－碘－５－氨基喹啉（ＳＡＩＡＱ）的合成。用元素分析、红外光谱法确定了其结构。测定了ＳＡＩＡＱ的酸度常数Ｋａ１＝２．４０×１０＾－４，Ｋａ２＝２．９８×１０＾－９。在ｐＨ３．５０￣５．００范围内ＳＡＩＡＱ与Ｇａ＾３＋形成稳定的荧光螯合物，且在λｅｘ／λｅｍ＝４２８ｎｍ／５４０ｎｍ产生强烈荧光。其荧光强度与Ｇａ＾３＋的浓度在１．５μｇ／Ｌ￣２６０μｇ／Ｌ范围内呈线性关系，     

钪—水杨醛苯甲酰腙高灵敏度荧光反应及其应用

研究了水杨醛苯甲酰腙（ＳＡＢＨ）与钪荧光反应新体系的最佳条件。在ｐＨ＝６．４乙醇／水（６．２：３．８）溶液介质中，形成络合物的组成比１：３（钪、试剂），λｅｘ／λｅｍ＝３８５ｎｍ／４５５ｎｍ，建立钪荧光分析法的线性范围为０￣１００μｇ／Ｌ；相对标准偏差１．５％；检出下限为０．０２５μｇ／Ｌ。考察了３０种共存离子的干扰情况，方法成功用于地质中样中痕量钪的测定。     

荧光法测定硼的研究

研究了新试剂２－［（５′－甲基－２′－胂酸茯苯）偶氮］－１，８二羟基－３，６－萘二磺到与硼的荧光性能。在ｐＨ６．７的磷酸氢二钠－磷酸二氢钾缓冲介质中，硼与试剂形成１：２的强荧光配合物，其λｅｘ／λｅｍ＝２３５ｎｍ／３６７ｎｍ，Ｂ（Ⅲ）含量在０￣２００μｇ／Ｌ范围内呈良好线性关系，检测限为０．６２９μｇ／Ｌ，建立了测定微量硼的新方法。该方法应用于茶叶及淀粉等亲品中微量硼的测定，结果满意。     

水杨醛—5—溴—水杨酰腙与锌的高灵敏度荧光反应及其应用

合成了新荧光试剂水杨醛－５－溴－水杨酰腙（ＳＡＢＳＨ），详细研究了试剂与锌的荧光反应新体系的最适宜条件．在ｐＨ７．９的异丙醇／水（体积比１∶１）溶液中，该试剂与Ｚｎ２＋形成配合物，组成比为１∶２（金属∶试剂），λｅｘ／λｅｍ＝３９３ｎｍ／４６５ｎｍ．所建立锌的荧光分析方法的线性范围为０～４００μｇ／Ｌ，相对标准偏差为１．２％，检出限为１．３μｇ／Ｌ．考察了３６种离子的干扰情况．方法成功地用于面粉、大米、人尿和矿泉水中痕量锌的测定．     

新试剂N—间甲苯基—N′—（氨基对苯磺酸钠）硫脲（MMPT）的合成及其在…

本文合成新试剂Ｎ－间甲苯基－Ｎ′－（氨基对苯磺酸钠）硫脲（ＭＭＰＴ）经红外，紫外，核磁，元素分析等测试，确定其结构，研究测定了试剂与４０多种种离子的反应及其配合物的表观洋吸光系数，它可作为Ｃｕ＾２＋（ｍ＝０．０１５μｇ，ｃ＝０．５μｇ／ｍＬ），Ａｇ＾＋（ｍ＝０．１μｇ，ｃ＝３．３μｇ／ｍＬ）的新鉴定试剂和光度法测定Ｐｄ＾２＋（ε３０９．７＝６．３２×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，Ｐｔ（Ⅳ）     

表面活性剂增敏铍试剂Ⅱ荧光法测定痕量锰

在碱性条件下，Ｍｎ（Ⅱ）与铍试剂Ⅱ形成１；２的荧光络合物，其荧光峰为λｅｘ＝λｅｍ＝３６７／４６７（ｎｍ），表面活性剂十二烷基苯磺酸钠对体系具有强烈增敏作用，基于此建立了痕量锰的测定方法。本文研究了测定的最佳条件，即０．０１％铍试剂Ⅱ４．０ｍＬ，０．１ｍｏｌ／ＬＮａＯＨ６．０ｍＬ，１％ＳＤＢＳ ４．０ｍＬ，反应温度为９０℃，时间１０ｍｉｎ，线性范围为０－１６０μｇ／Ｌ，回归方程Ｘ（μｇ／Ｌ）＝２．     

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.     

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.     

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.     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.