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1.
伯胺N1923萃取铬(Ⅵ)的研究   总被引:4,自引:0,他引:4  
研究了伯胺N1923从硫酸介质中对铬(Ⅵ)的萃取,分配法、红外光谱法等的研究结果表明:萃合物组成为RNH:·HCr_2O_7和(RNH_3)_2Cr_2O_7,求得了相关萃取反应的平衡常数,同时对含铬(Ⅵ)有机相进行了初步反实验,结果表明,以NaOH溶液进行的反萃效果较好.  相似文献   

2.
采用放射性同位素198Au示踪法研究了伯胺N1923和TBP从碱性氰化液中萃取金(Ⅰ),考察了酸化率、水相pH值、萃取剂浓度等对萃取率的影响,以及NaOH对载金有机相的反萃作用。结果表明,TBP含量大于20%,酸化的N1923与KAu(CN)2摩尔比值在1:1时,金能够完全被萃取。载金有机相可采用0.lmol·L-1的Na0H溶液定量反萃。机理研究表明,伯胺和TBP萃取Au(CN)2-,符合BC类协同萃取机理。当金浓度大于10g·L-1时,在萃取有机相中形成纳米级的聚集体。  相似文献   

3.
伯胺N1923萃淋树脂吸萃钯的研究   总被引:2,自引:0,他引:2  
伯胺N_(1923)萃淋树脂吸萃钯的研究程德平,夏式均(杭州大学化学系杭州310008)关键词钯,萃淋树脂,吸附伯胺萃取剂N(1923)用以萃取金属离子有不少研究[1-3],但以N(1923)萃淋树脂作固定相的萃取色层研究未见报道。本文研究了此树脂在?..  相似文献   

4.
研究了二(2,4,4-三甲基戊基)膦酸(BTMPPA,HA)的正辛烷溶液从盐酸介质中萃取钍(Ⅳ)的机理。在未控制离子强度下,萃取平衡反应为:,在控制离子强度为1.0mol/L时,萃取反应为用饱和法确定的萃合物组成为ThCIA_3.计算了萃取反应的平衡常数及热力学函数。研究了饱和萃合物的IR和NMR谱。  相似文献   

5.
伯胺N1923在不同稀释剂中萃取盐酸平衡   总被引:4,自引:0,他引:4  
用两相滴定法考察了伯胺N1923在煤油、氯仿、四氯化碳、甲苯、1,2-二氯乙烷和甲基异丁基酮等稀释剂中对盐酸的萃取,提出了处理萃取平衡的数学方法,观察到伯胺N1923与HCl形成的铵盐萃合物在不同稀释剂中存在不同程度的聚合,并确定了聚合度,讨论了稀释剂极性铵盐聚合度的影响,认为铵盐的这种聚合实际上是它在有机溶剂中形成了反相胶团,其间的作用力可认为是“范德华力”。  相似文献   

6.
研究了1,9-双(1-苯基-3-甲基-5-氧代吡唑-4-基)壬二酮-[1,9](BPMPND,H2A)与三辛基氧膦(TOPO,B)的氯仿溶液,从硝酸介质中对La(Ⅲ)、Dy(Ⅲ)的协同萃取,计算了体系的酸性协萃系数RA和协萃系数R,用斜率法测得协萃合物的组成为LaA·HA·B和DyA·HA·B,计算了协萃平衡常数,研究了温度对协萃反应的影响,用萃取法制得了固态协萃合物,并对其组成、IR及TG-DTA进行了研究.  相似文献   

7.
研究了1,9-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)壬二酮-(1,9)(BPMPND,H2A)与三辛基氧膦(TOPO,B)的氯仿溶液,从硝酸介质中对La(Ⅲ),Dy(Ⅲ)的协同萃取,计算了体系的酸性协萃系数RA和协萃系数R,用斜率法测得协萃合物的组成LaA.HA.B和DyA.HA.B计算了协萃取平衡常数,研究了温度对协萃反应的影响,用萃取法制得了固态协萃合物,并对其组成,IR及TG  相似文献   

8.
研究了伯胺N_(1923)萃淋树脂在N_(1923)成盐及不成盐时吸附钯的反应机理,通过等摩尔系列法、斜率法、红外光谱及核磁共振谱法对吸萃物的组成及吸萃机理进行了探讨。  相似文献   

9.
研究了二(2,4,4-三甲基戊基)膦酸的正辛烷溶液从盐酸介质中萃取钍的机理。在未控制离子强度下,萃取平衡反应为:Th^4++Cl^-+3(HA)2(o)→ThClA3(HA)3(o)+3H^+。在控制离子强度为1.0mol/L时,萃取反应为Th^4++2Cl^-+3(HA)2(O)→ThCl2A2.(HA)4(P)+2H^+。用饮和法确定的萃合物组成为ThClA3.计算了萃取反应的平衡常数及热力学  相似文献   

10.
伯胺N1923萃淋树脂吸萃AgNO3的性能及机理的研究   总被引:6,自引:0,他引:6  
本文研究了伯胺N1923萃淋树脂的合成方法和此萃淋树在酸性体系中吸萃AgNO3性能及不同因素对其静态分配比的影响,通过多种方法确定其萃合物的组成为Ag(RNH2)2NO3并用红外光谱探讨了该萃淋树脂吸萃AgNO3的机理。  相似文献   

11.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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%).  相似文献   

15.
An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6ag and imidazo[1,5-a]quinoxalines 7ah by the reaction of 2-imidazolyl anilines 4ac with aryl aldehydes 5ak under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4ab was found to be instrumental for the success of the reaction.  相似文献   

16.
The Diels-Alder reactivity of 1,2-heteroborines (H4C4B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.  相似文献   

17.
A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd2(dba)3-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.  相似文献   

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