吲哚乙酸与磷钼黄反应及其极谱分析的研究

在ＮＨ３－ＮＨ４Ｃｌ缓冲溶液中（ｐＨ＝９．５），吲哚乙酸与磷钼黄的还原产物在滴汞电极上于－１．１０Ｖ（ｖｓ．ＳＣＥ）处产生一灵敏的极谱波，该波波高与吲哚乙酸的浓度在１．０×１０－７－５．０×１０－６ｍｏｌ／Ｌ范围内成线性关系，检测下限为５．０×１０－８ｍｏｌ／Ｌ。如在上述还原产物中加入偶氮胭脂红Ｂ、孔雀绿、甲基紫等染料及聚乙烯醇，可使极谱波的灵敏度提高，使吲哚乙酸的浓度在５．０×１０－８－１．０×１０－６ｍｏｌ／Ｌ范围内与波高成线性关系，检测下限降低至１．０×１０－８ｍｏｌ／Ｌ。     

阿霉素在钴离子注入修饰电极上的电化学行为及其应用

阿霉素在０．１ｍｏｌ／Ｌ ＨＡｃ－ＮａＡｃ（ｐＨ４．６２）缓冲溶液中用注入钴的修饰玻碳电极为工作电极进行伏安测定,得到一良好的还原峰;Ｅｐ＝－０．５２２Ｖ（ｖｓ．ＳＣＥ）。峰电流与阿霉素浓度在１．４×１０＾－６－１．４×１０＾－６ｍｏｌ／Ｌ和１．４×１０＾－６－５．６×１０＾－５ｍｏｌ／Ｌ范围内呈线性关系,。     

乳酸环丙沙星单扫描示波极谱法研究

研究了乳酸环丙沙星的极谱伏安行为，在ｐＨ＝８．３的０．０２ｍｏｌ／Ｌ，ＮＨ４Ｃｌ－ＮＨ３．Ｈ２Ｏ底液中，乳酸环丙沙星能产生１个灵敏的还原峰，峰电位为－１．６１Ｖ，其导数峰高与浓度在３．９×１０＾－８～１．８×１０＾－６ｍｏｌ／Ｌ和１．８×１０＾６～１．１×１０＾－５ｍｏｌ／Ｌ范围内呈现良好的线性关系，相关系数ｒ＝０．９９９７，检测下限为２．５×１０＾－８ｍｏｌ／Ｌ，用于乳酸环丙沙星注射液的测定，相     

哌仑西平的单扫描示波极谱法测定

本报道一种测定哌仑西平的单扫描示波极谱法，在０．１ｍｏｌ／ＬＮＨ４Ｃｌ－ＮＨ３．Ｈ２Ｏ（ｐＨ８．０±０．１）缓冲液中，哌仑西平有一极谱还原波，其峰电位为－１．５１Ｖ（ｖｓ．ＳＣＥ），其一阶导数峰高与哌仑西闰浓度在６．６×１０＾－７－４．６×１０＾－６ｍｏｌ／Ｌ（ｒ＝０．９９８１）和６．６×１０＾－６－１．６×１０＾－５ｍｏｌ／Ｌ（ｒ＝０．９９９１）范围内有线性关系，检测限为３．４×１０－７ｍｏｌ     

溶出伏安法测定水中痕量钴

在０．０１ｍｏｌ／ＬＮＨ．Ｈ２Ｏ－ＮＨ４Ｃｌ和３．０×１０＾－５ｍｏｌ／Ｌ安息香缩氨基硫脲体系中，钴产生一灵敏的还原波，其峰电位是－０．９４Ｖ（ｖｓ．ＳＣＥ），峰电流与钴的浓度在２．０×１０－８－１．０×１０＾－６ｍｏｌ／Ｌ范围内成直线关系，检测限为５．０×１０＾－９ｍｏｌ／Ｌ，该法测定水中痕量钴结果令人满意。     

脑益嗪的吸附伏安特性及其测定

在ｐＨ２．３的ＫＣｌ－ＨＣｌ底液中，脑益嗪在汞电极上有一还原峰。其导数峰电位为－１．４７Ｖ（ＳＣＥ）；线性范围１．０×１０＾－７～１．０×１０＾－６ｍｏｌ／Ｌ；最低检测限为１．０×１０＾－７ｍｏｌ／Ｌ。用多种电化学手段证明，脑益嗪的还原属于反应物弱吸附的不同逆过程。该法用于样品中脑益嗪含量的测定，结果令人满意。     

锡—邻菲咯啉络合物吸附极谱波的研究及应用

研究了锡－邻菲咯啉体系的极谱行为，在ｐＨ＝２．５０的０．１０ｍｏｌ／Ｌ氯乙酸－氯乙酸钠介质中，在单扫描极谱上，Ｓｎ－邻菲咯啉络合物于－０．４１Ｖ电位处产生一良好的吸附还原波。波高与Ｓｎ的浓度在２．０×１０＾－８－４．０×１０＾－６ｍｏｌ／Ｌ范围内呈线性关系；检出限为１．０×１０＾－８ｍｏｌ／Ｌ Ｓｎ，对合金标样中的锡进行测定，取得了满意的结果。     

淋必治的极谱研究

在０．１ｍｏｌ／Ｌ ＨＡｃ－ＮａＡｃ（ｐＨ４．５０）支持电解质中，淋必治（ＳＰＥ）有一灵敏的示波极谱导数还原峰，峰电位Ｅｐ＝－０．９８Ｖ（ｖｓ．ＳＣＥ）。峰电流与ＳＰＥ的浓度在２．０×１０＾－７￣８．０×１０＾－５ｍｏｌ／Ｌ范围内呈线性关系，最低检出限为５．０×１０＾－８ｍｏｌ／Ｌ。该法用于注射针剂中ＳＰＥ含量的测定。，结果良好。文中对ＳＰＥ的极谱行为、电极过程及反应机理进行了探讨。     

头孢哌酮钠的伏发行为及其应用研究

头孢哌酮钠在０．０５ｍｏｌ／Ｌ Ｈ２ＳＯ４溶液中,形成一良好的示波极谱导数峰。峰电位为－０．８２Ｖ（ｖｓ．ＳＣＥ）。峰电流与头孢哌酮钠的浓度在１．０×１０＾－７－２．０×１０＾６ｍｏｌ／Ｌ范围内成线性关系。检出限为５．０×１０＾－８ｍｏｌ／Ｌ。回收率在９４．０％－１０２．０％之间。并用于尿样的测定,得到满意的结果。     

托美汀的吸附伏安法研究

在０．２ｍｏｌ／Ｌ ＮＨ３－ＮＨ４Ｃｌ底液中，托美汀在悬汞电极上有一灵敏的还原峰。峰电位为Ｅｐｃ＝－１．４８Ｖ，该峰具有明显的吸附性，峰电流ｉｐｃ与ＴＯＬ浓度在４．０×１０＾－９－７．０×１０＾－７ｍｏｌ／Ｌ范围内呈线性关系；检出限为５．０×１０＾－１０ｍｏｌ／ｌ，用该法测定了片剂ＴＯＬ的含量，结果良好。     

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%.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.