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本文比较了1-苯基,3-甲基,4-三氟乙酰吡唑酮(5)(代号为HAPZ-8113F,以HA表示)与多种多碳亚砜和双亚砜(以S表示)对于三价铈的协同萃取效应,以二辛基亚砜的协萃能力为最高。并进一步研究了以二辛基亚砜为中性萃取剂,在硝酸和盐酸体系申,和HAPZ-8113F协同萃取Ce(Ⅲ)时的混合萃合物组成。它们分别是:CeAs和CeA3·NO3·S以及CeA2·Cl·HA和CeA3·Cl·S。从归一化标绘图中推算了各有关的平衡常数。还制得了HAPZ-8113F与钕的固体萃合物及HAPZ-8113F、二甲基亚砜与钕的固体协车合物。它们的组成分别为NdA3·HA和NdA3·S。 相似文献
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双(十二烷基亚磺酰)乙烷溶剂萃取钯及其机理的研究 总被引:2,自引:0,他引:2
本文研究用双(十二烷基亚磺酰)乙烷萃取钯的性能,在KI存在下从7mol/L盐酸介质中用含有BDSE的氯仿能定量萃取钯,有机的钯可被硫脲或氨溶液反萃继之用TMK-TritonX-100光度法测定,研究了萃取的最佳条件及干扰情况,斜率法测得萃合物组成为Pd:I:BDSE=1:2:1,红外光谱证实萃合物中BDSE的二个亚砜以硫原子与钯配位,萃合物为异位体络合物,提出了选择性萃取分离钯的新方法。 相似文献
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研究了正丁基辛基亚砜(n-BOSO)、正戊基己基亚砜(n-PHSO)和乙基十二烷基亚砜(n-ED-SO)与1,10-双(1′-苯基-3′-甲基-5′-氧代吡唑-4-基)癸二酮-[1,10](H_2A)对铀(Ⅵ)的协同萃取行为。用斜率法测得协萃合物的组成为UO_2A·B(式中B分别代表n-BOSO、n-PHSO和n-EDSO),求得协萃平衡常数,用萃取法制得了固态协萃合物,并用元素分析、UV及IR光谱对其进行了表征。 相似文献
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以亚砜的模型化合物正丁基正辛基亚砜液-液萃取Au(Ⅲ),对萃取剂及萃取配合物的1H NMR、13C NMR波谱特征进行讨论,研究了萃取时萃合物的结构及其动态变化.作者认为有机相中存在Au(Ⅲ)在正丁基正辛基亚砜(BOSO)与配合物之间快速交换的过程,该过程有利于Au(Ⅲ)从水相向有机相转移,也是形成NMR波谱特征的主要原因.核磁共振实验也说明了在两种酸度下Au(Ⅲ)均与亚砜基团中的氧原子配位,但萃取机理有所不同,核磁共振波潜的分析给出了萃取机理的直接证据. 相似文献
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本文研究了1-苯基-3-甲基-4-苯甲酰基吡唑啉酮-5(PMBP)与二苯基亚砜(DPSO)的甲苯溶液在高氯酸介质中对铒(Ⅲ)的协同萃取,测得了萃合物的组成和各萃取反应的平衡常数及热力学函数增量. 相似文献
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酰代呲唑酮作为金属元素萃取剂的研究(Ⅱ)——不同基团取代的呲唑酮对于铈(Ⅲ)的萃取及其与二辛基亚砜的协同萃取作用 总被引:1,自引:0,他引:1
本文研究了不同基团取代的酰代吡唑酮对铈(Ⅲ)的萃取。采用斜率法和同位素示踪技术,测得它们在HCl和HNO3体系中的萃合物组成和萃取平衡常数;还研究了它们与二辛基亚砜对铈(Ⅲ)的协同萃取。研究过程中,以HTTA作为对照。 相似文献
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研究了柠檬酸、酒石酸、乳酸、丁二酸、亚氨基二乙酸及乙酰丙酮为配合剂时的U(Ⅳ)-U(Ⅵ)Redox排代色谱学。着重讨论了羧酸为配位剂时提高铀同位素富集因子的可能性及途径。 相似文献
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Total Synthesis of (6R,10R,13R,14R,16R,17R,19S,20R,21R,24S, 25S,28S,30S,32R,33R,34R,36S,37S,39R)‐Azaspiracid‐3 Reveals Non‐Identity with the Natural Product 下载免费PDF全文
Nathaniel T. Kenton Dr. Daniel Adu‐Ampratwum Dr. Antony A. Okumu Dr. Zhigao Zhang Dr. Yong Chen Dr. Son Nguyen Dr. Jianyan Xu Dr. Yue Ding Dr. Pearse McCarron Dr. Jane Kilcoyne Prof. Dr. Frode Rise Prof. Dr. Alistair L. Wilkins Dr. Christopher O. Miles Prof. Dr. Craig J. Forsyth 《Angewandte Chemie (International ed. in English)》2018,57(3):805-809
A convergent and stereoselective total synthesis of the previously assigned structure of azaspiracid‐3 has been achieved by a late‐stage Nozaki–Hiyama–Kishi coupling to form the C21?C22 bond with the C20 configuration unambiguously established from l ‐(+)‐tartaric acid. Postcoupling steps involved oxidation to an ynone, modified Stryker reduction of the alkyne, global deprotection, and oxidation of the resulting C1 primary alcohol to the carboxylic acid. The synthetic product matched naturally occurring azaspiracid‐3 by mass spectrometry, but differed both chromatographically and spectroscopically. 相似文献
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I. I. Zseltvay O. I. Zseltvay V. P. Antonovich 《Russian Journal of General Chemistry》2012,82(2):180-189
The features are considered of binding carboxylic acids (HR) as dimeric solvated copper(II) complexes at the copper(II) extraction
with chloroform under substoichiometric conditions, with excess of the metal ion in the aqueous phase. The fundamental difference
in the optimization of the quantitative extraction of copper(II) in the form of any carboxylate with a maximum ratio of Cu:R
and the total binding with carboxylic acids to form the copper complex of the minimum stoichiometry was noted. It was found
that quantitative binding of HR occurred at the extraction of mixed-ligand acetate-carboxylate copper(II) complexes without
control over the aqueous phase acidity when acetic acid medium or copper(II) acetate was used, but not copper chloride, nitrate,
perchlorate, or sulfate. The possibility of determination by extraction-photometric method by the color of the Cu(II) complex
was shown that was suitable only to those carboxylic acids, whose logarithm of the partition coefficient in the water-chloroform
mixture was higher than three. 相似文献
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Donaldson EM 《Talanta》1980,27(2):79-84
A simple and moderately rapid method for determining 0.001% or more of molybdenum in ores, iron and steel is described. After sample decomposition, molybdenum is separated from the matrix elements, except tungsten, by chloroform extraction of its alpha-benzoinoxime complex from a 1.75 M hydrochloric-0.13 M tartaric acid medium. Depending on the amount of tungsten present, molybdenum, if necessary, is back-extracted into concentrated ammonia solution and subsequently separated from coextracted tungsten by chloroform extraction of its xanthate complex from a 1.5M hydrochloric-0.13M tartaric acid medium. It is ultimately determined by atomic-absorption spectrophotometry, at 313.3 nm, in a 15% v/v hydrochloric acid medium containing 1,000 microg/ml of aluminium as the chloride, after evaporation of either extract to dryness with nitric, perchloric and sulphuric acids and dissolution of the salts in dilute ammonia solution. 相似文献
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A new iso-amyl benzothiazolyl sulfoxide (ABSO) was synthesized and used in the extraction of Pd(II) from hydrochloric acid media. Pd(II) was extracted quantitatively from 0.1 M HCl with ABSO in benzene (0.5 M). Ammonia solution (2.0 M) could be used as stripping agent. ABSO and Pd(II) form a 2:1 adduct [Pd (ABSO)2Cl2] in the extraction. X-ray crystal structure determination revealed PdCl2(ABSO)2 is a square-planar complex in which ABSO acts as a neutral unidentate ligand coordinated with palladium(II) via the thiazolyl N atom. 相似文献
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A calix[6]arene carboxylic acid derivative was utilized as an extractant for various amino compounds including amino acids. The host compound exhibited a high extractability compared to that of commercially available extractants such as di(2-ethylhexyl)phosphoric acid (D2EHPA). The important factors for amino acid extraction were found to be its cyclic structure and its cavity size, the functional carboxylic groups, and the length of the alkyl chains. The hydrophobicity and the ionic property of guest molecules also affect the extraction efficiency. Calix[6]arene forms a stable complex with a guest molecule by entrapping it into the cavity. The molecular geometries of calixarene before and after extraction were also discussed using computational calculations with the PM3 type of semi-empirical method. 相似文献
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The solvent extraction behavior of multiple proton ionizable p-tert-butylcalix[4]arene and [6]arene carboxylic acid derivatives towards indium has been investigated along with an acyclic monomeric analogue from weakly acidic media into chloroform. The extraction mechanism is ion exchange and carboxylic acid groups are adequate ligating sites for extraction. The cyclic structure of calixarene ligands to accommodate the potential guest species and the cooperativity effect of multifunctional groups significantly affect the complexation behavior and calixarene derivatives are found to be excellent extractants over the monomeric analogue. The composition of the extracted complex depends on the solution pH and attempts to determine the composition of the extracted complex for the extraction of indium have been stymied by complications arising from the formation of polynuclear species of indium and bridged polymeric species of calixarene carboxylic acid derivatives. One mole of calix[4]arene derivative extracts 2.5 moles of indium whereas the calix[6]arene derivative tends to extract 4.0 moles of indium. The loaded indium is back extracted with 1 mol dm(-3) hydrochloric acid solution. Though quantitative back extraction of indium was achieved from the fully loaded calix[6]arene derivative, it was only achieved up to 85% in the case of the calix[4]arene derivative. 相似文献
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水溶液中Eu3+与meso-四(4-磺苯基)卟啉(TPPS)不易形成卟啉络合物,但在乙酸、酒石酸、丙二酸等共存时,在循环伏安图上可得一对Eu3+还原-氧化的可逆或准可逆峰,此峰与Eu3+在NaClO4底液中的还原峰相比,峰电位正移,峰电流增高。从6种Eu3+-羧酸络合物与TPPS共存时的实验中证明这些络合物并没有和TPPS形成三元络合物,而是吸附在汞电极上的TPPS产生电催化作用。 相似文献
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Mechanistic studies of a palladium-mediated decarboxylative olefination of arene carboxylic acids are presented, providing spectroscopic and, in two instances, crystallographic evidence for intermediates in a proposed stepwise process. Sequentially, the proposed pathway involves carboxyl exchange between palladium(II) bis(trifluoroacetate) and an arene carboxylic acid substrate, rate-determining decarboxylation to form an arylpalladium(II) trifluoroacetate intermediate (containing two trans-disposed S-bound dimethyl sulfoxide ligands in a crystallographically characterized form), then olefin insertion and beta-hydride elimination. Because of the unique mode of generation of the arylpalladium(II) trifluoroacetate intermediate, a species believed to be substantially electron-deficient relative to phosphine-containing arylpalladium(II) complexes previously studied, it has been possible to gain new insights into those steps that are common to the Heck reaction, namely, olefin insertion and beta-hydride elimination. The present results show that there are notable differences in reactivity between arylpalladium(II) intermediates generated by decarboxylative palladation and those produced in conventional Heck reactions. Specifically, we have found that more electron-rich alkenes react preferentially with an arylpalladium(II) trifluoroacetate intermediate formed by decarboxylative palladation, whereas an opposite trend is found in conventional Heck reactions. In addition, we have found that the aralkylpalladium(II) trifluoroacetate intermediates that are formed upon olefin insertion in the present study are stabilized with respect to beta-hydride elimination as compared to the corresponding phosphine-ligated aralkylpalladium(II) complexes. We have also crystallographically characterized an aralkylpalladium(II) trifluoroacetate intermediate derived from arylpalladium(II) insertion into norbornene, and this structure, too, contains an S-bound dimethyl sulfoxide ligand; the ipso-carbon of the transferred aryl group and trifluoroacetate function as the third and fourth ligands in the observed distorted square-planar palladium(II) complex. 相似文献
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A new extraction method for the determination of tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) in sediments based on extraction with tartaric acid and methanol has been developed. Tin species were extracted from sediment samples using focused microwave technology, then ethylated with sodium tetraethylborate (NaBEt4) and analyzed by isotope dilution (ID) gas chromatography-mass spectrometry (GC-MS). The advantages of such methodology in comparison with other established extraction methods for the routine speciation analysis of organotin compounds are discussed with respect to sulfur interferences co-extracted from complex matrices.Interferences from elemental sulfur are normally found with acetic acid extraction, but with tartaric acid extraction these interferences were eliminated, demonstrating selective extraction.The accuracy of the analytical procedure was established by analyzing a certified reference material (CRM) (PACS-2, marine sediment) and comparing the results to the certified values. Good agreement between determined and certified values for butyltin compounds was obtained. Finally, some complex sediment samples collected from San Vicente's Bay, Chile, were analyzed with the proposed methodology, demonstrating its potential value for monitoring butyltins in environmental samples with high concentrations of sulfur compounds. 相似文献