CL-P204萃淋树脂分离铟(Ⅲ)镓(Ⅲ)锌(Ⅱ)

铟、镓作为重要的电子工业材料,在高技术领域有着广泛的应用．但是由于它们都是非常稀有而且分散的金属,至今以其为主要成份的主矿床尚未发现,它们通常是以微量的组分共生于锌矿等矿物中,因此,有关从锌矿中分离铟、镓的研究具有重要意义．由于铟、镓、锌３种离子的性...     

CL-P_(204)萃淋树脂吸萃铟(Ⅲ)的性能和机理

有关分离回收稀有金属铟和镓的研究和应用已有较多报道．过去主要是采用溶剂萃取法，但由于工业料液中钢、镓的含量很低，溶剂萃取法往往达不到高效分离回收的目的．同时由于该法使用了大量有机溶剂和革取剂，造成环境污染，这就大大限制了溶剂萃取法在分离回收钢、嫁的应用．离子交换法可以弥补溶剂革取法在工业料液中分离回收钢、嫁的这些不足，但由于该法存在着处理量小、选择性差、树脂的种类少等问题，因而该法也没能在工业上得以广泛应用．革淋树脂法兼有溶剂革取法和离子交换法的优点，克服了二者的不足，近来有人已将该法用于稀土、…     

电感耦合等离子体原子发射光谱法测定铝酸钠溶液中的镓

正镓是一种低熔点、高沸点的银白色金属,被广泛用于半导体材料、太阳能薄膜、永磁材料等电子领域。镓在地壳中的含量极少,全球储量约为23万t。镓本身不能单独形成矿物,常伴生于铝土矿、铬铁矿等中,质量分数为0.002%~0.02%,镓主要是作为其他金属冶炼的副产物提取[1]。在氧化铝生产过程中,铝酸钠溶液中的镓不断被富集,质量浓度高达     

荧光镓的电化学行为及稀土—荧光镓络俣吸附波研究

本文研究了荧光镓在PH2－10底液中的伏安行为，证实其偶氮基首先还原为氢化偶氮、，然后通过氢化偶氮的歧化反应或二电子还原生成相应的胺化物，荧光镓在汞电极上的吸附符合Frumkin等温式，在PH9．5的氯性底液中可获得稀土－荧光镓的络合吸附波,对重稀土的检测限为1．0×10^-8mol/L，测定了电活性络合物的组成及发光材料BaFCl:Ho中钬的含量。     

铝镓咔咯配合物的发光性质、堆积效应与轴向配位作用

本文合成了2种第三主族金属铝和镓咔咯配合物Al(tpfc)、Ga(tpfc)、Al(tpfc)(Py)2、Ga(tpfc)(Py)。测定了在甲苯溶液中,铝和镓咔咯的电子光谱、荧光光谱、荧光量子产率及荧光寿命。在不同溶剂作用下,铝和镓咔咯的电子吸收光谱和荧光光谱的峰位置和强度存在差异。在二氯甲烷溶液中,轴向配体吡啶能促进铝和镓咔咯的π-π堆积。不同轴向配体与金属咔咯的结合能力为:咪唑>4-甲基咪唑>吡啶,铝比镓的咔咯配合物有更强的结合轴向配体的能力。     

丙烯聚合中硅烷类外给电子体及其复配技术研究进展

聚丙烯是一类重要的通用塑料,主要用于汽车工业、家用电器、电子、包装及建材家具等领域。在现有聚丙烯工业生产中,通常加入外给电子体来影响丙烯聚合过程,达到调控产品物理性能的目的。本文对丙烯聚合中硅烷类外给电子体及其复配技术进行了综述,并对外给电子及其复配技术在聚丙烯新产品开发上的应用进行了分析。     

含在口中就熔化的金属

一提到金属 ,人们自然联想到那是坚硬、耐磨、耐高温的象征。但谁能想到世界上还有含在人的口中就熔化的金属呢 ?这就是 1871年俄国化学家门捷列夫在编制化学元素周期表时曾预言的“类铝”、1875年法国化学家布瓦博德朗从闪锌矿中离析出的金属———镓 (Ga)。如果把一小块固体镓含在人的口中 ,要不了多久 ,固体镓就熔化为液体镓 ,在嘴里滚来滚去。这是因为镓的熔点仅为 2 9.78℃ ,比正常人的体温 (37℃ )还要低几度。镓的原子序数是 31,原子量是 6 9.72 3,属ⅢA族 ,电子构型为 (Ar) 3d10 4s24 p1,氧化态为 +1、+3,固体镓为蓝灰色、液体镓…     

荧光镓的电化学行为及稀土-荧光镓络合吸附波研究

本文研究了荧光镓在pH 2～10底液中的伏安行为。证实其偶氮基首先还原为氢化偶氮,然后通过氢化偶氮的歧化反应或二电子还原生成相应的胺化物。荧光镓在汞电极上的吸附符合Frumkin等温式。在pH 9.5的氨性底液中可获得稀土-荧光镓的络合吸附波。对重稀土的检测限为1.0×10^-8mol/L。测定了电活性络合物的组成及发光材料BaFCl:Ho中钬的含量。     

硒的分析方法研究

硒是一种分散的稀有元素，它在电子工业，医疗等部门有广泛的用途和诱人的发展前景。本文介绍了一些硒的定性和定量分析方法。     

镓-有机络合物的示波极谱测定

虽然镓的极谱行为已经引起重视,但利用镓的螯合物性质来进行定量测量比较困难。在中性溶液中,波形由于离子的水解而扭曲,在酸性介质中,波又被H_3O~+的还原而难以辨认,在强碱性溶液中,镓酸盐不能被还原。因此,长期以来,极谱法测定镓很少应用,研究报导也少。 Latlmer和Копаиская曾进行过镓的有机化合物的极谱测定,他们所制定的在pH4.6±     

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.     

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.     

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.     

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.     

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.     

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.