新试剂N-间甲苯基-N′-(氨基对苯磺酸钠)硫脲(MMPT)的合成及其在分析化学中的应用

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多种离子的反应及其配合物的表观摩尔吸光系数，它可作为Ｃｕ２＋（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Ｐｄ２＋（ε３０９．７＝６．３２×１０４Ｌ·ｍｏｌ－１·ｃｍ－１）、Ｐｔ（Ⅳ）（ε７５４．４＝８．５８×１０４Ｌ·ｍｏｌ－１·ｃｍ－１）等的显色剂，方法灵敏度高、选择性好，用于阳极泥、人发、矿石及催化剂中上述元素的鉴定或测定，均获满意结果。     

丁基罗丹明B-铜钨杂多酸光度法测定微量铜

在聚乙烯醇（ＰＶＡ）存在下，丁基罗丹明Ｂ（ＢＲＢ）与铜钨杂多酸形成离子缔合物。缔合物的形成条件为ｃＨ２ＳＯ４＝１．２ｍｏｌ／Ｌ，ｃＷＯ２－４＝６．１×１０－５ｍｏｌ／Ｌ，ｃＢＲＢ＝３．８×１０－５ｍｏｌ／Ｌ和ＰＶＡ０．０８％。缔合物的最大吸收波长位于５７０ｎｍ，摩尔吸光系数ε＝１．６６×１０６Ｌ·ｍｏｌ－１·ｃｍ－１，铜量在每２５ｍＬ０～０．５μｇ范围内服从比耳定律，检测限为每ｍＬ０．６５ｎｇ（ｎ＝１２），对每ｍＬ１８ｎｇＣｕ测定的ＲＳＤ为０．８５％（ｎ＝１０）。缔合物至少稳定１５０ｈ，其摩尔比为Ｃｕ∶Ｗ∶ＢＲＢ＝１∶１２∶５，红外图谱表明铜钨杂多酸具有Ｋｅｇｇｉｎ结构。考察了４０多种共存离子的影响，大多数常见元素不干扰。本法已用于天然水、自来水、降水、人发、中药和蔬菜中铜的测定，结果满意。     

二安替比林对甲氧基苯基甲烷与锰(Ⅳ)的高选择性显色反应研究及应用

在碱性介质中，空气氧化Ｍｎ（Ⅱ）为Ｍｎ（Ⅳ），然后在酸性介质中，Ｍｎ（Ⅳ）氧化二安替比林对甲氧基苯基甲烷（ＤＡｐＭＭ）生成黄色产物，λｍａｘ＝４５０ｎｍ，ε＝５．４５×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。锰含量在０～２０μｇ／２５ｍＬ内符合比尔定律。方法用于钢样中锰的测定，结果满意     

丁基罗丹明B—钼酸盐光度法连续测定铈和钪

在聚乙烯醇（ＰＶＡ）存在下，丁基罗丹明Ｂ（ＢＲＢ）分别与铈钼、钪钼杂多酸络阴离子形成离子缔合物，其最大吸收均位于５７０ｎｍ，表面摩尔吸光度分别为εＣｅ＝３．９６×１０＾６Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，εＳｃ＝４．７１×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，服从比耳定律范围分别为０－２４μｇ／Ｌ Ｃｅ和０－６０μｇ／ＬＳｃ，测定极限为Ｃｅ１．０μｇ／Ｌ（ｎ＝１２）和Ｓｃ１．９μｇ／Ｌ（ｎ＝１０），对     

钌（Ⅲ）－钼酸盐－罗丹明B离子缔合显色反应的研究及分析应用

钌（Ⅲ）钼酸盐－罗丹明Ｂ离子缔合显色体系分光光度测定钌，λｍａｘ为５７０ｕｍ，ε＝９．０５×１０５Ｌ·ｍｏｌ（－１）·ｃｍ（－１），相对标准偏差２．５％。线性范围０～１．２μｇ／２５ｍＬ。大量常见金属不干扰Ｒｕ的测定。方法用于某些岩矿和冶金产品中钉的测定，获得满意结果。     

Cu（Ⅰ）的高灵敏度显色反应的研究Ⅱ．及其在绿茶测定中的应用

本文研究了在硫酸介质中，Ｃｕ（Ⅰ）－ＳＣＮ￣－罗丹明Ｂ体系当有明胶和聚乙醇辛基苯基醚存在时的显色反应。该反应的λｍａｘ＝５９５ｎｍ，ε＝２．０×１０５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），铜在０～５．００μｇ／２５ｍＬ范围内具有良好的线性关系。据此拟定的分析方法，用于测定绿茶中的痕量铜，选择性好，灵敏度高，结果满意。     

Meso—四—（3,5—二溴—4—羟基苯）卟啉分光光度测定食品中微量铅

研究了溴代卟啉试剂（ＤＢＨＰ）Ｐ分光光度法测定食品中微量铅。在０．０８ｍｏｌ／ＬＮａＯＨ介质中,铅与Ｔ（ＤＢＨＰ）Ｐ反应生成一橙黄色配合物,λｍａｘ＝４７９ｎｍ,ε＝２．２×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。铅在０－１２μｇ／２５ｍＬ范围内符合比耳定律,用于食品中微量铅的测定,获得满意结果。     

阴离子表面活性剂－溴化十二烷基二甲基苄基铵－溴百里酚蓝显色反应的分光光度法研究

本文研究了溴化十二烷基二甲基苄基铵－溴百里酚蓝与阴离子表面活性剂显色反应的适宜条件。结果表明，在ｐＨ７．４～８．２范围内阴离子表面活性剂与题示试剂形成１：２：１的绿色离子缔合物，其最大吸收峰位于６１４ｎｍ处。表现摩尔吸光系数分别为：＝３．９９×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）；＝３．７０×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）；＝１．７１×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。ＳＤＢＳ在０～１９５μｇ／１０ｍＬ，ＳＤＳ在０～１５８μｇ／１０ｍＬ，ＳＬＳ在０～６０μｇ／１０ｍＬ范围内遵守比耳定律。该法用于河水和生活废水中阴离子表面活性剂测定，结果满意。     

Mo－SCN－CV显色体系测定钼的研究与应用

本文研究了在阿拉伯树胶存在下，以Ｃｕ（２＋）为催化剂的钼－硫氰酸盐－结晶紫高灵敏新显色体系及钼的分光光度测定条件。在０．３２ｍｏｌ／ＬＨ２ＳＯ４介质中，缔合物的最大吸收波长λｍａｘ＝６００ｎｍ，表观摩尔吸光系数ε＝５．３８×１０５Ｌ·ｃｍ（－１）ｍｏｌ（－１），Ｍｏ（Ⅵ）在０－７μｇ／２５ｍＬ范围内符合比耳定律。方法用于钢铁中钼的测定，结果准确。     

用钼酸盐和罗丹明B连续光度法测定铈和钪

聚乙烯醇存在下，铈或钪钼杂多酸与罗丹明Ｂ（ＲＢ）形成离子缔合物，最大吸收均位于５７０ｎｍ，摩尔吸光系数分别为１．１６×１０＾６和５．６２×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，ｃｍ＾－１，０－１．２μｇ／２５ｍＬＣｅ和０－２．０μｇ／ｍＬＳｃ服从比耳定律，检测限１．５ｎｇ／ｍＬＣｅ（ｎ＝１０）和１．１ｎｇ／ｍＬＳｃ（ｎ＝９）。缔合物的摩尔比为Ｃｅ：ｍＯ：ＲＢ＝１：６：３和 Ｓｃ：Ｍｏ：ＲＢ＝１：１     

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.     

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.     

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.     

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.