Silver Extraction from Hydrochloric Acid Solutions with the Disulfide of Bis(2,4,4-trimethylpentyl)Dithiophosphinic Acid

Silver extraction from hydrochloric acid solutions with the disulfide of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (L) in toluene is described in this work. Based on the analysis of the extraction data, it was concluded that silver extraction is due to the formation of the compound AgCl?2L in the organic phase. An increase in the concentration of hydrochloric acid in the aqueous phase leads to a decrease in AgCl extraction because of the formation of non-extractable anionic complexes of silver. Solvent extraction efficiency decreases in the series octanol > decane > chloroform > toluene, which is due to the preferential solvation of the extracted complex by the solvent. A significant increase in the extraction of silver chloride with disulfide in the presence of octanol is caused by the strong interaction of the extracted compound and the alcohol, due to the chloride ion solvation by octanol. The possibility of using the disulfide for silver extraction from hydrochloric acid solutions containing metal impurities (Ni, Cu, Co, Zn, Fe (III), and Na) has been demonstrated. The degree of silver recovery in one stage was 98.62%, while the extractant showed high selectivity toward silver: the separation factors of silver over metal (β_Ag/_Me) ranged from 9000 to 30,000. Almost complete silver stripping from the organic phase was achieved when using a mixture of thiourea and sulfuric acid solutions. The extraction characteristics of the disulfide are much better as compared to that of the well-known commercially available extractant triisobutylphosphine sulfide. The disulfide of bis(2,4,4-trimethylpentyl)dithiophosphinic acid can be used for efficient extraction of silver from industrial hydrochloric acid solutions of different origin.     

Manganese extraction with mixtures of bis(2,4,4-trimethylpentyl)dithiophosphinic acid and trioctyl phosphine oxide

It was shown that a strong synergistic effect (S ≈ 4000) takes place when extracting manganese (II) from sulfate solutions with mixtures of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (CYANEX 301) and trioctyl phosphine oxide (TOPO. The synergistic effect is caused by the formation of the mixed complex Mn-HR-TOPO. Analysis of the manganese partition between organic and aqueous phase as well as of the IR and electron paramagnetic resonance spectra of the extracts showed that manganese forms a hexacoordinated complex with the dithiophosphinate ions and TOPO with an octahedral geometry. The composition of the complex can be presented as MnR₂?2TOPO.

Examples of the possible use of the CYANEX 301 and trialkyl phosphine oxide (TAPO, CYANEX 923) mixtures when processing manganese-containing liquors are given.     

Investigation of the State of Bis(2,4,4‐Trimethylpentyl)dithiophosphinic Acid in Nonane and Toluene Solutions

An IR spectroscopy method is used to examine the state of nonane and toluene diluted bis(2,4,4‐trimethylpentyl)dithiophosphinic acid (HR) in the concentration range of 0.025–1.0 M. It was found that in contrast to the “inert” solvent nonane, in which marked self‐association of the dithiophosphinic acid due to the formation of intermolecular SH…S hydrogen bonds begins at an HR concentration of ～0.1 M, in the aromatic diluent toluene this process begins at HR_total ?0.4 M. This result is explained by the interaction of the proton of the S‐H group of the dithiophosphinic acid with the π‐electron system of the toluene aromatic ring and the formation of SH…π hydrogen bonds, preventing the self‐association of the organic acid. The presence of the monomeric, dimeric, and tetrameric forms of the extractant in solution was shown to best describe the bis(2,4,4‐trimethylpentyl)dithiophosphinic acid‐nonane system. The formation constants of the dimers (K₂ = 0.78 ± 0.07) and tetramers (K₄ = 3.42 ± 0.26) have been calculated.     

Nickel(II) Extraction from Sulphate Media with Bis (2,4,4‐Trimethylpentyl)Dithiophosphinic Acid Dissolved in Nonane

The paper presents data on nickel(II) extraction from sulphate solutions with nonane‐diluted bis(2,4,4‐trimethylpentyl)dithiophosphinic acid (HR). An IR spectroscopy method is used to examine the state of HR in nonane, and it was shown to exist as a monomer up to a concentration of 0.1 M. With a further increase in concentration, the acid forms associated species. The value of the concentration of the monomeric form is determined as a function of the total HR concentration in nonane in the range of 0.0–1.0 M. Based on the comparative analysis of the extraction equilibrium data together with information from the visible and IR absorption spectra of the nickel extract, the configuration of the nickel(II) complex in the organic phase was determined to be a low‐spin, square‐planar complex. The complex composition was found to correspond to the formula NiR₂. The complex is hydrated, with the water very likely being bonded in the outer coordination sphere.     

二(三氯甲基)碳酸酯法合成酰氯化合物

采用二(三氯甲基)碳酸酯与相应的羧酸反应,合成了8个具有代表性的酰氯化合物：顺,反-2,2-二甲基-3-(2,2-二氯乙烯基)环丙烷羧酰氯、顺-2,2-二甲基-3-(2-氯-3,3,3-三氟丙-1-烯基)环丙烷羧酰氯、氯乙酰氯、三氯乙酰氯、苯甲酰氯、邻氯苯甲酰氯、邻甲基苯甲酰氯、反-3-苯基-2-丙烯酰氯,收率为82．1％-91．7％,纯度为96．4％-98．9％,     

手性酒石酸衍生物DMTA合成工艺研究

研究了手性酒石酸衍生物D-或L-二对甲氧基苯甲酰酒石酸(DMTA)的合成工艺。在三氟化硼-乙醚络合物催化下,D-(或L-)酒石酸与对甲氧基苯甲酰氯和二氯亚砜作用生成D-(或L-)二对甲氧基苯甲酰酒石酸酐,然后酸酐在丙酮-水体系中水解成D-(或L-)二对甲氧基苯甲酰酒石酸,两步总收率82.73%,光学纯度大于99%。     

双(三正丁基)氧化锡参与的异氰酸酯环三聚反应

研究三种异氰酸酯与双（三正丁基）氧化锡在等摩尔比时的反应。证明相互作用的产物是以缔合形式存在的相应锡的氨基甲酸酯。双（三正丁基）氧化锡碳酸酯,氨基甲酸酯及其在异氰酸酯环三聚反应中水解产物催化活性的研究,证明氨基甲酸酯或它与异氰酸酯相互作用的产物,在双（三正丁基）氧化锡参加下,对三聚过程的催化起决定作用。     

双(三甲基硅基)二亚胺的合成研究

以双(三甲基硅基)氨基锂为起始原料,分别与氯化亚砜、三溴化磷反应,合成了双(三甲基硅基)硫二亚胺和双(三甲基)硅胺基-三甲基硅亚氨基磷,然后通过两者间的硫原子迁移反应,合成了标题化合物.通过梯度温度下的减压冷凝,实现了目标化合物的分离和纯化,并采用核磁共振、紫外-可见吸收光谱进行了结构表征,根据最大吸收波长计算得其跃迁能为2.53 ×10-19J.     

Fractional factorial design for the optimization of supercritical carbon dioxide extraction of La, Ce and Sm ions from a solid matrix using bis(2,4,4-trimethylpentyl)dithiophosphinic acid + tributylphosphate

In this study, La³⁺, Ce³⁺ and Sm³⁺ were removed from a solid matrix using supercritical CO₂ which contained bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex 301) as a chelating agent and tributylphosphate (TBP) as a co-extractant. The fractional factorial design, 2⁵⁻¹, was employed to optimize the SFE of these ions from spiked filter paper matrices. Effect of five experimental factors: amount of Cyanex 301, flow rate, temperature, pressure and amount of TBP and each factor at two levels on the SFE of these ions were studied and optimized. The results showed that these ions could be quantitatively extracted from the solid matrix at amount of Cyanex 301 of 0.14 g, flow rate of 4 ml min⁻¹, 313 K, 250 bar and amount of TBP of 30 μl. Finally, by employing a regression analysis a model was proposed. Results showed that obtained recoveries are similar to those predicted by the model.     

Extraction Behavior of Am(III) and Eu(III) from Nitric Acid Medium in Tetraoctyldiglycolamide-Bis(2-Ethylhexyl)Phosphoric Acid Solution

The extraction behavior of Am(III) and Eu(III) in a solution of tetra-octyldiglycolamide (TODGA), bis(2-ethylhexyl)phosphoric acid (HDEHP), and n-dodecane (n-DD) was studied to understand the role of TODGA and HDEHP in the combined solvent system. The extraction behavior of these metal ions was compared with those observed in TODGA/n-DD and HDEHP/n-DD. The effect of various parameters such as concentrations of HNO₃, TODGA, and HDEHP on the distribution ratio of Am(III) and Eu(III) was studied. Synergistic extraction of both the metal ions observed at lower acidities (<2.0 M) was attributed to the involvement of TODGA and HDEHP for extraction. However, the extraction of Am(III) and Eu(III) in the combined solvent was comparable with that observed in TODGA at higher acidities. The slope analysis of the extraction data confirmed the involvement of both the extractants at all acidities investigated in the present study.     

二（8—羟基喹啉）铜的固相合成及其反应的研究

使用醋酸铜和８－羟基喹啉在室温条件下的固相化学反应合成了二（８－羟基喹啉）铜。用等温电导法和ＤＳＣ研究了其反应,发现反应分两步进行：首先反应形成一醋酸一（８－羟基喹啉）合铜,之后形成产物。该反应的速率方程和速率常数亦被确定。     

二羟甲基丙酸的合成研究

合成了二羟甲基丙酸,对合成产品进行了表征及合成条件的探讨。     

二二甲亚砜合硫氰酸镉（DSTC）晶体的合成、结构、表征与晶体生长

合成了金属有机配合物晶体二二甲亚砜合硫氰酸镉Cd(SCN) 2 (C2 H6 OS) 2 (简称DSTC)。用X射线四圆衍射方法确定了此化合物的晶体结构。用元素分析、红外光谱对其进行了化学表征。首次在DMSO/水的溶剂中 ,生长出尺寸为 3 5mm× 12mm× 11mm透明单晶。     

Synergistic Silver Extraction from Hydrochloric Acid Solutions with Triisobutylphosphine Sulfide in the Presence of Organic Proton-Donor Additives

Silver chloride extraction from hydrochloric acid solutions with triisobutylphosphine sulfide (CYANEX 471, L) in the presence of organic proton-donor additives (HR) was studied. Both alkyl-, bromo-, nitro-substituted phenols, and organic acids of various structures were used as additives. A new synergistic effect (S) was found to take place in the presence of the additives. The degree of the synergistic effect in the systems containing phenols decreases in the series 4-nitrophenol > 4-bromophenol > 4-tert-butylphenol > 2,6-dimethylphenol > 2-methyl-6-cyclohexylphenol > 2,6-bis(tert-butyl) phenol. In the systems containing organic acids, the following series is observed: dinonylnaphthalenesulfonic acid (DNNSA) > 4-tert-butylphenol > caprylic acid > di(2-ethylhexyl)phosphoric acid > bis(2,4,4-trimethylpentyl)phosphinic acid. Based on the analysis of the extraction data and the IR and NMR spectra of the extracts, it was concluded that an increase in the silver extraction with CYANEX 471 in the presence of HR is due to the formation of the compound [AgCl?2L?HR] in the organic phase. It was shown that a mixture of CYANEX 471 and 4-tert-butylphenol can be used for the highly selective extraction of silver from hydrochloric acid solutions containing metal impurities (Ni, Cu, Co, Zn, Fe(III), and Na). The mixtures of CYANEX 471 with alkylphenols or DNNSA, in which the high synergistic effects (S ≥ 10 and ≥ 50, respectively) take place, can efficiently be used for processing different industrial silver chloride solutions.     

Bis(cyclopentadienyl)zirconium Dichloride for Alkylation of Heteroaromatics and Synthesis of Bis(indolyl)methanes

Bis(cyclopentadienyl)zirconium dichloride catalyzed alkylation of heteroaromatics with epoxides results in the formation of 3-alkylated heteroaromatics in high yields. Cp₂ ZrCl₂ is also found to be an efficient catalyst for the electrophilic substitution reaction of indoles with aldehydes and ketones to afford the corresponding bis(indolyl)methanes in high yields with complete regioselectivity.     

Phenol Removal from Aqueous System by Bis(2-ethylhexyl) Sulfoxide Extraction

Solvent extraction is generally considered as one of the important and effective techniques to remove toxic phenol from wastewater. This paper explores the solvent extraction of phenol from wastewater using bis(2-ethylhexyl) sulfoxide (BESO) as extractant. Various parameters such as equilibrium time, the volume percentage of BESO, pH value, and ionic strength of the aqueous solution on the phenol extraction were investigated. The results indicated that BESO exhibited excellent performance of phenol extraction. The extraction percentage increased from 97.26% to 99.47%, varying the BESO concentration from 10% (v/v) to 30% (v/v). The extraction percentage decreased with increasing temperature in the range of 298-343 K. FTIR spectra of fresh and phenol loaded BESO organic phase indicated the existence of the hydrogen bonding interactions between S=O groups and phenol molecules. The relationship between log D and log [BESO] suggested the stoichiometry of the extracted species was a 1:1 complex, namely, [PhOH]·[BESO]. Phenol stripping from the loaded organic phase by sodium hydroxide was feasible, and more than 99% of phenol could be stripped when the NaOH concentration was 0.5 mol L^?1. The results obtained established that BESO/kerosene extraction system has potential for practical application in the phenol removal and recovery.     

二（1-咪唑基）甲烷的合成研究

以二溴甲烷和咪唑为原料合成了二(1-咪唑基)甲烷.确定适宜的合成条件为:在乙腈溶液中,咪唑、二溴甲烷、氢氧化钾投料摩尔比为1∶0.45∶1.20,60℃反应3.5 h后再回流反应1.5 h,经重结晶提纯,产率可达83.2%.通过熔点测试和1HNMR谱图分析对产物结构进行了确证.本法具有耗时短、副反应少、产率高等特点.     

双(三氯甲基)碳酸酯在有机合成中的应用新进展

本文着重讨论了双（三氯甲基）碳酸酯-BTC作为替代光气的新原料以其独特的性质，在有机合成、药物合成等相关反应的最新应用。     

二(N,N-二甲基胺基乙基)己二酸酯的合成

采用二月桂酸二丁基锡为催化剂,通过己二酸二甲酯与N,N-二甲基乙醇胺进行酯交换反应合成了二(N,N-二甲基胺基乙基)己二酸酯.实验考察了反应温度、催化剂量、反应时间及物料配比等因素对反应收率的影响.最佳工艺条件为:温度120℃,反应时间5h,n(己二酸二甲酯):n(二甲胺基乙醇):n(二月桂酸二丁基锡)=1:6:0.048.在优化条件下,产品收率为81.6%(以己二酸二甲酯计),产物经IR、'HNMR表征了结构.     

2,2-二(溴甲基)-1,3-丙二醇的合成

以季戊四醇和４０％氢溴酸溶液为原料,冰醋酸为催化剂,经取代反应、减压分离、纯化和干燥等步骤合成了具有优良性能的反应型阻燃剂２,２ 二（溴甲基） １,３ 丙二醇,以季戊四醇计,产品收率为８０．８％。实验确定了氢溴酸与季戊四醇的最佳摩尔比为２．５∶１,最佳反应时间为６～８ｈ,最佳反应温度为回流温度。先用等体积的甲苯和水混合物分离合成产物,再用热水重结晶进行纯化。经元素分析、熔点测定和红外光谱分析予以确证。