Interfacial behavior of primary amine N1923 and the kinetics of thorium(IV) extraction in sulfate media

The influences of additive, diluents, temperature, acidity of the aqueous phase on the interfacial behavior of primary amine N1923 in sulfate media have been investigated using the Du Nouy ring method. In addition, the effect of concentration of thorium(IV) loaded in the organic phase on the interfacial tension has also been studied. The interfacial tension isotherms are processed by matching different adsorption equations such as the Gibbs and the Szyszkowski. The surface excess at the saturated interface (Gamma (max)) and the minimum bulk concentration of the extractant necessary to saturate the interface (C-min) under different conditions are calculated according to two adsorption equations to be presented in comprehensive tables and figures. It appears that primary amine N1923 has strong interfacial activity and behaves very differently in various diluents systems. The surface excess at saturated interface increase with the type of diluerits in the following order: chloroform < aromatic hydrocarbons < aliphatic hydrocarbons. The relationship between the interfacial activity and kinetics of thorium extraction by primary amine N1923 has been discussed by considering different factors. However, the interfacial activity of primary amine N1923 is only a qualitative parameter suggesting the interfacial mechanism for thorium extraction, it cannot give strong evidence quantitatively supporting this mechanism.

Facile syntheses and characterization of hyperbranched poly(ester-amide)s from commercially available aliphatic carboxylic anhydride and multihydroxyl primary amine

A new method for synthesis of novel hyperbranched poly(ester-amide)s from commercially available AA' and CBx type monomers has been developed on the basis of a series of model reactions. The hyperbranched poly(ester-amide)s with multihydroxyl end groups are prepared by thermal polycondensation of carboxyl anhydrides (AA') and multihydroxyl primary amine (CBx) without any catalyst and solvent. The reaction mechanism in the initial stage of polymerization was investigated with in situ H-1 NMR. In the initial stage of the reaction, primary amino groups of 2-amino-2-ethyl-1,3-propanediol (AEPO) or tris(hydroxymethyl)aminomethane (THAM) react rapidly with anhydride, forming an intermediate which can be considered as a new AB(x) type monomer. Further self-polycondensation reactions of the AB. molecules produce hyperbranched polymers. Analysis using H-1 and C-13 NMR spectroscopy revealed the degree of branching of the resulting polymers ranging from 0.36 to 0.55. These hyperbranched poly(ester-amide)s contain configurational isomers observed by C-13 and DEPT C-13 NMR spectroscopy, possess high molecular weights with broad distributions and display glass-transition temperatures (T(g)s) between 7 and 96 degreesC.

Synergistic extraction of zinc(II) and cadmium(II) with mixtures of primary amine N1923 and neutral organophosphorous derivatives

Synergistic extraction of zinc(IT) and cadmium(11) from hydrochloric acid solution with primary amine N1923 and neutral organophosphorus derivatives Cyanex 923 and Cyanex 925 is the focus of this paper. Extraction mechanisms are discussed as well as how the acidity of the aqueous phase, the composition of the organic phase, and the experimental temperature affect the rates of extraction of metal ions. Differences between synergistic efficiency of Zn(II) and Cd(II) with mixtures of primary amines N1923 and either Cyanex 923 or Cyanex 925 are observed. The equilibrium constants, the composition, and the formation constants of the extracted complexes as well as the values of the thermodynamic functions are calculated. According to the synergy coefficient formula, the synergy effect on the extraction of Zn(II) is in the following order:N1923 + Cyanex 925 > N1923 + Cyanex 923 This order is reversed in the case of cadmium(II). For the same synergistic system, the extraction rate follows the order: Zn(II) > Cd(II). Furthermore, the stereochemical structures of the various extractants and their effect on metal ion extraction rate are also investigated.

Extraction of zinc(II) and cadmium(II) by using mixtures of primary amine N1923 and organophosphorus acids

The extraction of zinc(II) and cadmium(II) from a chloride medium by mixtures of primary amine N1923 and organophosphorus acids [di-(2-ethylhexyl)-phosphoric acid, 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH/EHP), isopropyl phosphonic acid 1-hexyl-4-ethyloctyl ester, bis(2,4,4-trimethylpentyl) phosphinic acid, bis(2,4,4-trimethylpentyl) monothiophosphinic acid, and bis(2,4,4-trimethylpentyl) dithiophosphinic acid] has been studied in the present paper. Results show that only the mixtures of N1923 + HEH/EHP and N1923 + Cyanex272 have synergistic effects on zinc(II), but the other mixtures have no evident synergistic effects. All six mixtures have no evident synergistic effects on cadmium(H). A possible explanation of the different extraction abilities is given based on the structure of the extractants. Furthermore, the possibilities of separating zinc(II) and cadmium(II) with these mixtures are investigated according to the extractabilities. It is possible to separate Zn2+ from bulk cadmium with N1923 and HEH/EHP mixtures and separate Cd2+ from bulk zinc with N1923 and Cyanex301 mixtures.

Synergistic extraction of zinc(II) by mixtures of primary amine N1923 and Cyanex272

The extraction of zinc(II) and cadmium(II) from chloride solution by mixtures of primary amine N1923 and Cyanex272 (HA) was studied. The synergistic effect was observed for the extraction of zinc(II) while no synergistic effect for cadmium(II), which makes it possible to separate zine(II) and cadmium(II) with the mixtures. The results showed that zinc(II) was extracted as (RNH3Cl)(3) . ZnCIA instead of ZnA(2) . 2HA which was extracted by Cyanex272 alone. The extraction mechanism was discussed and the formation constants and thermodynamic functions were determined. The separation factors between zinc(II) and cadmium(II) were calculated.

Studies on synergistic extraction of rare earths(III) with HBTMPTP and primary amine N1923

The synergistic extraction of rare earths(III) with binary systems containing HBTMPTP and primary amine N1923 from sulfuric acid medium was observed, The syner gistic extraction factor(R) decreased with increasing atomic number of lanthanides. Through the methods of slope analysis, constant mole and saturation titration, the synergistic extraction stoichiometry was obtained, The thermodynamic function was calculated, The IR spectra of the saturated synergistic extraction completely confirmed the mechanism.

SOLVENT-EXTRACTION OF TERBIUM(III,IV) PERIODATE COMPLEXES WITH QUATERNARY AMINE

The differences between the solvent extraction of Tb(III) and Tb(IV) periodate complexes with quaternary amine were studied carefully for the first time. The effects of extractant concentration, phase ratio, the pH value of stock solution, salting-out agent, extractant form, diluent, and extraction time were comprehensively investigated. Under optimal conditions the separation factor between Tb(IV) and Tb(III) periodate complexes is over 5.5.

Sulfamide-amine alcohol catalyzed enantioselective alkynylation of aromatic ketones

The new readily available sulfamide-amine alcohol 11 was found to be effective in catalyzing enantioselective phenylacetylene addition to aromatic ketones without using another central metal, providing the chiral tertiary propargylic alcohols in good yields (up to 83%) and enantioselectivities (up to 83% e.e.). The conditions of this catalytic process are both mild and Simple, (c) 2005 Elsevier B.V. All rights reserved.

七氟丁酸酐有序超薄膜的制备与结构

在涂敷有聚合物PEI涂层的单晶硅表面上制备了HFBA单层分子膜,接触角测量及XPS结果表明,HFBA在PEI表面产生了化学吸附发生了化学键合(酰胺键),形成了低表面能的HFBA单分子层膜.这一吸附反应的动力学行为可能表现为Langmuir单分子层化学吸附.

噻吩胺基稀土配合物的合成、表征

本论文共合成了两种类型12个稀土金属配合物和一个硅化合物,分别对它们进行了红外、核磁等表征，对其中的9个配合物进行了晶体结构的测定。考察了配体结构和反应条件对所生成的配合物结构的影响，研究了稀土单烷基配合物的反应性，以及稀土双烷基配合物在烷基铝和有机硼盐的共同作用下对丁二烯聚合的催化活性和选择性。主要工作内容和结论如下： (1) 合成了噻吩苯胺配体(HL1)，该配体与(Lu，Y)稀土三烷基化合物反应，通过C–H活化和烷基消除反应制备了稀土(Lu，Y)单烷基配合物1和2，配体以少见的C，N模式配位，S原子并不参与配位。配体(HL1)与Sc三烷基化合物反应制备了配体分别以C, N和N, S配位的双配的Sc配合物5。 (2) 通过改变反应时间和溶剂体系，HL1与稀土钇三烷基化合物反应可得到罕见的由稀土烷基化物和胺化物两部分组成的配合物3，它们通过噻吩环上活化的C原子连接在一起。HL1和Lu(CH2SiMe3)2(THF)2LiCH2SiMe3在甲苯和正己烷溶剂中反应可得到以L12Lu(CH2SiMe3)2为阴离子，Li(THF)4为阳离子的离子对4。 (3) 研究配合物1和2的反应性。1和2与过量的PhSiH3反应得到中心金属与Si元素交换的Si化合物。 (4) 合成了噻吩苯基膦胺配体(HL2-4)和苯基膦胺配体(HL5)配体。HL2-5与稀土(Y, Lu和Sc)三烷基化合物反应制备了稀土双烷基配合物6，7，8，9，10，11和12。进一步研究了稀土金属双烷基配合物6–12对丁二烯的催化特性，发现该系列催化剂具有独特的催化性质，能够催化丁二烯高反1，4-聚合（91.3%），得到的聚合物分子量在1到2万之间，分子量分布较窄(1.4–1.6)。 (5) 研究了金属钇(Y)，镥(Lu)，钪(Sc)三种中心金属对丁二烯聚合活性和反式1，4选择性的影响，发现催化剂对丁二烯聚合活性和反1，4选择性取决于配合物的中心金属原子，其中选择性最高为钪配合物，催化活性最佳的为钇配合物。 (6) 研究了配体HL2-4的N-芳环上的取代基分别为甲基，乙基，异丙基时催化体系对丁二烯反式1，4聚合活性和选择性的影响，发现随着N-芳环上取代基空间位阻的增大，催化剂活性逐渐下降，选择性逐渐增加，但当其取代基为异丙基时，过大的空间位阻导致活性和选择性同时有明显的下降。我们通过改变噻吩基为苯基，比较了相同聚合条件下含噻吩基的稀土双烷基配合物和含苯基的稀土双烷基配合物对丁二烯聚合活性和选择性的影响，发现噻吩环的存在对催化剂的活性和选择性有较大的影响。 (7) 在相同催化剂条件下，研究了不同聚合条件(不同类型的AlR3，不同类型的Borate，Al/Ln比等)对丁二烯反1，4聚合活性和选择性的影响。 我们发现，在AlR3和Borate这两种影响因素中，以烷基铝的类型对催化剂催化活性和选择性的影响最大，而有机硼盐的影响则比较轻微，其中以烷基铝为AliBu3，Borate为[B(C6F5)4][Me2NHPh]时，反1，4选择性为最佳。Al/Ln增大并不能够显著增加催化剂的活性，对选择性的影响也并不明显，相反，随着铝比的增加，聚合过程中的链转移增加，导致分子量下降，对于该系列稀土烷基催化剂，最佳Ln/Al 为10。

含空穴传输基团PPV的合成与性能研究

该论文以提高聚苯撑乙烯（PPV）类发光聚合物的空穴传输性能为主要目的,通过将具有较高空穴传输能力的芳胺类小分子基元引入发光聚合物分子链,设计并合成了一系列含芳胺基元的PPV聚合物.另外,还通过对分子结构进行设计和控制,获得了红绿蓝三基色发光.最后还利用在共轭分子主链上引入具有三维空间位阻的侧链基团,获得了高效率的绿色发光聚合物材料.

IMPROVEMENT OF STRUCTURAL INSTABILITY OF THE ION-SENSITIVE FIELD-EFFECT TRANSISTOR (ISFET)

Three causes involved in the instability of the ISFET are proposed in this study. First, it is ascertained that hydroxyl group resident at the surface of the Si3N4 film or in the electrolyte solution is most active and subject to gain or loss of electrons. This is one of the main causes for ISFET structural instability. Secondly, the stability of the pH-sensitive FET varies with deposition conditions in the fabrication process of the ISFET. This proves to be another cause of ISFET instability. Thirdly, the pH of the measured solution varies with the measuring process and time, contributing to the instability, but is not a cause of the instability of the pH-ISFET itself. We utilized the technique of readjusting and controlling the ratio of hydroxyl groups to amine groups to enhance the stability of the ISFET. Our techniques to improve stability characteristics proved to be effective in practice.