新显色剂5—（4—氯—2—羟基苯偶氮）罗丹宁与银（Ⅰ）显色反应的研究和应用

本报道了新显色剂５－（４＇－氯－２＇－羟基苯偶氮）罗丹宁的合成及其光度法测定银的条件，在ｐＨ＝５．０的缓冲介质中，该显色剂与银形成黄色络合物，其络合比为Ａｇ（Ｉ）：Ｒ＝１：２，摩尔吸光系数为１．１×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１，用拟定的方法测定阳极泥，废定影液中银的含量，结果满意。     

安替比林基重氮氨基—2,4—二硝基苯与银（I）的显色反应及其应用

本文报道了安替比林基重氮氨基－２，４－二硝基苯（ＡＰＤＮＢＴ）与银（Ｉ）的显色反应，在吐温－８０存在下，ＰＨ＝９．０－１０．０的范围内，试剂与银（Ｉ）形成２：１的配合物；配合物对试剂的最大吸收在４８５ｎｍ处，ε为７．２×１０＾４Ｌ＾－１．ｍｏｌ．ｃｍ＾－１提出了消除阳离子干燥的银镜分离法；方法用于洞察工样及照相显影液中银的含是一定回收率为９６－１０３％，相对标准偏差小于２．０％。     

偶合反应化学发光法测定痕量银的研究

本将Ａｇ（Ⅰ）催化Ｓ２Ｏ＾２－８氧化Ｍｎ（Ⅱ）生成ＭｎＯ＾－４的催化反应与ＬｕｍｉｎｏｌＭｎＯ＾－４－ＯＨ＾－的化学发光反应相偶合，建立起一种新的灵敏测定痕量银的化学发光分析法，在所研究的优化条件下，该法测定银的选择性较好，检测限达到３．２×１０＾－１２ｇ／ｍＬＡｇ线性浓度范围为１．０×１０＾－１１－１．０×１０＾－５ｇ／ｍＬＡｇ，用于水样分析，结果较为满意。     

催化反应吸光光度法测定痕量银

研究了Ａｇ对亚铁氰化钾与邻菲罗啉显色反应的催化研究，建立了痕量银的催化吸光光度法。灵敏度为１．０×１０＾－３μｇ．ｍｌ＾－１，线性范围为０－０．４μｇ／２５ｍＬ。用于水样中痕量银的测定，结果满意。     

3,5—Br2—PADAP—IO^—30SCN—三元离子缔合物测定微量IO^— …

研究了３，５－Ｂｒ２－ＰＡＤＡＰ在酸性介质中质子化，与ＩＯ＾－３和ＳＣＮ＾－形成三元离子缔合物的最佳条件，其表现摩尔吸光系数为１．４＊１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，缔合物组成比为３，５－Ｂｒ２－ＰＡＤＡＰ：ＩＯ＾３：ＳＣＮ＾－＝１：１：１。     

二甲酚橙光度法测定含氧化稀土铝电解质中的氧化铝

在ＰＨ３．０－３．５的ＨＯＡｃ－ＮａＯＡｃ缓冲液中,二甲酚橙浓度较低时,二甲酚橙与铝形成稳定的红色络合物,络合物比为１：１表观摩尔吸光系数为ε５５５＝１．５３＊１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１,线性范围为０－０．５μｇ．ｍｌ＾－１。方法运用于含稀土铝电解质中氧化铝的测定,排除稀土干扰结果满意。     

偶合反应化学发光法测定痕量银的研究——K4Fe（CN）6—Luminol体系

将Ａｇ（Ｉ）催化Ｋ４Ｆｅ（ＣＮ）６的水合反应与Ｌｕｍｉｎｏｌ同Ｃｕ（ＣＮ）＾２－４的化学发光反应相偶合，建立起一种新的灵敏测定痕量银的化学发光分析法，在所研究的优化条件下，该法测定银的选择性较好，检测限达到４．０×１０＾－１３ｇ／ｍＬＡｇ线性浓度范围为１．０×１０＾－１２～１．０×１０＾－６ｇ／ｍＬＡｇ对４×１０＾－１１ｇ／ｍＬＡｇ（Ｉ）溶液连续１１次测定的ＲＳＤ≤３．５％，用于环境水和岩矿中银的     

2—（5—溴—2—吡啶偶氮）—5—二乙氨基酚与铅（Ⅱ）,锌（Ⅱ）络合平衡的双…

本用双系列线性回归法研究了Ｐｂ（Ⅱ），Ｚｎ（Ⅱ）与５－Ｂｒ－ＰＡＤＡＰ的络合反应，发现在ｐＨ５－６．５，３０％乙醇溶液中，Ｐｂ（Ⅱ）与５－Ｂｒ－ＰＡＤＡＰ形成１：１络合物，Ｚｎ（Ⅱ）主要形成１：２络合物。两种络合物的稳定常数（１ｇβ）分别为１１．１７，２２．３１，最大吸收波长分别为５７５，５５０ｎｍ，摩尔吸光系数分别为６．０１×１０＾４，１．３４×１０＾５Ｌ．ｍｏｌ＾－＾１．ｃｍ＾－＾１。     

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…

本文研究了溴化十二烷基二甲基苄铵－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。表观摩尔吸光系数分别为ε＾ＳＤＢＳ６１４＝３．９９×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１；ε＾ＳＤＳ６１４＝３．７０×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，ε＾ＳＬＳ６１４＝１．７１×１０＾４Ｌ．     

一阶导数分光光度法同时测定记忆合金电镀液和电镀层中铁和钯

在酸性介质中,铁和钯分别与亚硝基Ｒ盐络合形成绿色的Ｆｅ－ＮＲＳ和红色的Ｐｄ０ＮＲＳ,利用一阶导数分光光度法在水相中同时测定Ｆｅ和Ｐｄ。结果证明,两种络合物的摩尔吸光系数分别为１．９４×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾０１（对铁）和１．６３×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾１（对钯）;线性范围分别为０－５．６ｍｇ／ｌ（对铁）和０－７．０ｍｇ／Ｌ（对钯）;相对标准偏差均小于２．０％;回收率为９６５－１     

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.     

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.     

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%).