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1.
We have studied the nucleophilicity of the hydroperoxide anion relative to 4-nitrophenyl diethyl phosphonate (NPDEPS) in the presence of cetyltrimethylammonium bromide (water, 25 °C) while varying the acidity of the medium and the hydroperoxide anion concentration over a broad range. The increase in the reaction rate when the reaction is transferred to a micellar pseudophase is as high as ∼10-fold, which is explained by concentration effects. In CTAB micelles, as in water, the hydroperoxide ion is one of the most effective α-nucleophiles, and the size of the α-effect, characterized by the ratio of the second-order rate constants for reactions of HOO and OH anions with NPDEPS, remains practically constant and reaches a value of ∼50-fold. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 6, pp. 357–363, November–December, 2006.  相似文献   

2.
The kinetics and mechanism of the catalysis by ammonium hydrogen carbonate oxidation of methyl phenyl sulfide with hydrogen peroxide has been investigated. Using the classical pseudo-phase model of micellar catalysis, the basic parameters of the catalytic process have been determined: the binding constants of H2O2, the HCO 4 anion, and the substrate to the surface of the micelles, and also the second order rate constants for the oxidation of methyl phenyl sulfide in the micellar phase. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 5, pp. 281–287, September–October, 2006.  相似文献   

3.
王国芝  胡继文 《广州化学》2010,35(3):7-10,15
酚在碱性条件下与卤代烃反应生成相应的芳香醚,是典型的亲核取代反应,对于2,4-二硝基酚和二氟溴甲基膦酸二乙酯在碱性条件下的反应,其实验过程包括室温中和,甲苯回流脱水和亲核取代等三步反应。对产物进行了提纯和一系列的表征,结果发现主要生成了一种酚醚化合物。  相似文献   

4.
研究了新试剂 1 -( 2 ,6 -二氯 -4 -硝基苯 ) -3 -( 4-硝基苯 ) -三氮烯与镉的显色反应。在 Triton X-1 0 0存在下 ,于 p H=9.8~ 1 1 .0的 Na2 B4 O7-Na OH缓冲溶液中 ,镉与试剂有高灵敏的显色反应 ,生成 1∶ 3型黄色配合物 ,最大吸收波长为 44 5nm。用双峰双波长法测定 ,其表观摩尔吸光系数为 2 .85× 1 0 5L·mol- 1·cm- 1。用拟定的方法测定了人发和废水中的镉含量 ,标准加入回收率分别为 1 0 4.5%和 1 0 5.8% ,相对标准偏差分别为 3 .2 %和 4.1 %。  相似文献   

5.
The nucleophilicity of hydroxamate ions toward ethyl 4-nitrophenyl ethylphosphonate, diethyl 4-nitrophenyl phosphate, and 4-nitrophenyl 4-toluenesulfonate in water (µ=1, KCl, 25°C) is described by the Brø nsted equation (N=0.54, 0.70, and 0.59, respectively). In these reactions, hydroxamate ions act as typical -nucleophiles; they are more reactive than phenoxide ions with the same basicity by a factor of 300 to 800. In the series of hydroxamate ions, an anomalously high nucleophilicity was revealed for the anions possessing catalytic centers (in terms of general base catalysis), which are capable of providing anchimeric assistance in the transition state. An equation has been proposed, which relates the efficiency of such assistance in anions derived from aminohydroxamic acids to the pK a values characterizing their acidic and basic groups.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1384–1396.Original Russian Text Copyright © 2004 by Simanenko, Prokopeva, Popov, Bunton, Karpichev, Savelova, Ghosh.Deceased.This study was performed under financial support by the US Civil Research and Development Foundation (CRDF) (grant no. UC2-2489-DO-03).  相似文献   

6.
The interaction has been investigated of 1-(4-nitrophenyl)pyrrolin-2-one with aromatic aldehydes in acetic anhydride in the presence of catalytic amounts of pyridine. 1-(4-Nitrophenyl)pyrrolinium perchlorate has been synthesized and was put into a condensation reaction with aromatic aldehydes. As a result 5-arylidene-1-(4-nitrophenyl)pyrrolin-2-onium perchlorates were obtained. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1015–1021, July, 2006.  相似文献   

7.
We have studied the effect of different surfactants on the rate of diethyl sulfide (Et2S) oxidation by hydrogen peroxide and peroxymonocarbonate (HCO 4 - ) in aqueous solutions. In all the studied cases, the rate of the reaction between Et2S and H2O2 decreases as the surfactant concentration increases. The reaction of Et2S with HCO 4 - is catalyzed by cationic surfactants and inhibited by neutral and anionic surfactants.Translated from Teoreticheskaya i Éksperimentalnaya Khimiya, Vol. 40, No. 6, pp. 368–372, November–December, 2004.  相似文献   

8.
Pyrolyses of the reactively flame retarded polystyrene copolymers styrene/diethyl(acryloyloxyethyl)phosphate(S/DEAEP), styrene/diethyl(methacryloyloxyethyl)phosphate(S/DEMEP), styrene/diethyl(methacryloyloxymethyl)phosphonate(S/DEMMP) and styrene/diethyl(acryloyloxymethyl)phosphonate(S/DEAMP) have been investigated with a view to obtaining information pertinent to the mechanism of their flame retardant behaviour. Studies were also carried out on the additive polystyrene systems containing triethylphosphate (TEP) and diethylethylphosphonate (DEEP) for comparison. All the systems contained 3.5 wt% of phosphorus. A range of techniques were used, namely TG with EGA, DSC, SEM, laser and microfurnace pyrolysis mass spectrometry and isothermal pyrolysis/GC-MS, to study the decompositions under a range of conditions. In the case of the additive systems, the additive was shown to be evolved before polymer decomposition occurred. Very little, if any, char residues were observed. Thus the main mechanism of fire retardant action of the phosphorus incorporated into the polystyrene as an additive would occur in the vapour phase. This mechanism prevailed regardless of whether the additive was a phosphate (TEP) or a phosphonate (DEEP). The effectiveness of the fire retardant action would be limited as the fire retardant and fuel did not volatilise together. There was evidence that some interaction occurred in the condensed phase. In all the copolymers the phosphorus content of the char was substantial. This is characteristic of the condensed phase fire retardant action of phosphorus. SEM studies showed the interior of the char to be a network of channels which would give the char a sponge-like interior which would enhance thermal insulation. The surfaces were relatively dense thus providing a barrier to escape for any gaseous products formed in the interior. Char formation and cross-linking are assumed to be the result of the presence of the strong phosphoric and phosphonic acids resulting from initial pyrolysis. Since phosphonic is the weaker acid, the polymer degradation and release of volatile products may be less inhibited in the case of the phosphonate-containing copolymers compared to the phosphate-containing copolymers. This is consistent with their shorter times to ignition. There was also evidence for some potential phosphorus vapour phase fire retardant action as phosphorus-containing species were identified among the pyrolysis products for all samples. The rate of volatile evolution from the copolymers was reduced compared to that of the corresponding additive system.  相似文献   

9.
用DCNPNPT测定江水中季铵盐型阳离子表面活性剂   总被引:4,自引:0,他引:4  
利用三氮烯类试剂与季铵盐型阳离子表面活性剂形成离子缔合物可用于季铵盐型阳离子表面活性剂的测定。如用HDNPAPT[1]、HDAA[2]测定CTMAB、CPB,但其灵敏度有待提高。本文研究了显色剂1 (2,6 二氯 4 硝基苯) 3 (4 硝基苯) 三氮烯(DCNPNPT)[3]与阳离子表面活性剂的显色反应,结果表明,DCNPNPT与CTMAB、CPB反应的表观摩尔吸光系数分别为3 93×104L·mol 1·cm 1,和4 16×104L·mol 1·cm 1,是目前报道的用光度法测定季铵盐型阳离子表面活性剂较灵敏的体系之一。用此法测定了瓯江水中微量阳离子表面活性剂CTMAB、CPB的…  相似文献   

10.
合成了一种二维窗口型膦酸锆材料β-丙氨酸-N,N-双亚甲基膦酸锆(ZrNCP),采用X射线衍射仪、扫描电镜、透射电镜分析了合成产物的相组成和微观结构;利用N2吸脱附试验装置测定了合成产物对不同金属离子的吸附性能,考察了浓度、温度及pH对其吸附性能的影响.结果表明,合成产物内部存在大量分布均匀的微介孔,材料微观形貌为规整片状.随着金属离子半径的增大,ZrNCP对各种金属离子的平衡吸附量(mmol/g)呈逐渐减小趋势.  相似文献   

11.
The spectral kinetic characteristics of the triplet states of 1-(4-nitrophenyl)-3-methylpyrazole (1) and 1-ethyl-3-(4-nitrophenyl)-5-chloropyrazole (2) were studied by the laser nanosecond photolysis technique in different solvents. The triplet lifetimes (τT) of molecules 1 and 2 were found to depend strongly on the solvent nature. An increase in τT by approximately two orders of magnitude on going from nonpolar and polar aprotic solvents (τT ≤ 15 ns) to aqueous-acetonitrile solutions (τT = 1100 ns for a volume acetonitrile to water ratio of 1 : 3) was analyzed, taking into account the influence of the medium on the relative contribution of the n,π*- and π,π*-configurations to the lowest triplet state. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1115–1119, May, 2005.  相似文献   

12.
The radical telomerization of 3,3,3-trifluoropropene (TFP) with diethyl phosphate (or diethyl hydrogen phosphonate, DEHP) was investigated to synthesize fluorinated telomers bearing a phosphonate end-group, as H(TFP)nP(O)(OEt)2. Di-tert-butyl peroxide was the most efficient radical initiator. A careful structural study of typical TFP/DEHP telomers was performed by 1H, 19F, and 31P nuclear magnetic resonance spectroscopies. These analytical methods allowed us to prove the selective addition of the phosphonyl radical onto the hydrogenated side of TFP, while the telomers containing more than two TFP units were composed of TFP isomers containing normal and reversed adducts. The kinetics of telomerization led to the assessment of the first four order transfer constants giving an infinite transfer constant of 0.75 at 140 °C for DEHP.  相似文献   

13.
1 INTRODUCTIONSomeoforganophosphoruscompounds,includingmanyheterocycliccompoundscontainingphosphonogroup,havegoodbioactivityinorganism[1].Duetotheirrela-tionwithbiochemical/biological,pharmacologicalandpesticidalresearch,hetero-cycliccompoundscontainingphosphonogrouphavebeensynthesizedbysomeofnewsyntheticmethods,inwhichseveralnewbuildingblockwereused,suchasβ-phos-phonicenemines,[2,3]isocyanomethylphosphonate,[4]β-functionalγ-oxo-alkylphos-phonates,[5]andacetylenicphosphonate.[6]Inourpr…  相似文献   

14.
The nucleophilic reactivity of the typical -nucleophile hypobromite ion, generated by the organic complexes of the tribromide ion, toward 4-nitrophenyl diethylphosphonate in water and micelles of cetyltrimethylammonium bromide (CTAB) was studied. The BrO–CTAB system is one of the most effective for the decomposition of organophosphorus compounds; the concentrating effect of the reagents secures the rapid break down of 4-nitrophenyl diethylphosphonate in an aqueous–micellar medium with t 1/2 20 s (in water t 1/2 600 s).Yu. S. Simanenko: Deceased  相似文献   

15.
Neutral forms of hydroxylamine, N-methylhydroxylamine, and N,N-dimethylhydroxylamine are typical α-nucleophiles in water. In comparison with aryl anions of similar basicity their rate of reaction in the decomposition of 4-nitrophenyl diethylphosphonate is increased by about 102 times. Decomposition of the substrate is accelerated in cetyltrimethylammonium bromide micelles (about 4 to 30 fold). Hydroxylamine and its N-alkyl derivatives are the most effective low basicity nucleophiles. The sole factor responsible for the micellar effects is the concentration of the reagent in the surfactant micelles. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 4, pp. 231–236, July–August, 2007.  相似文献   

16.
吴文鹏  曹艳 《化学研究》2014,25(6):609-615
用密度泛函理论优化了三苯甲烷(1)和一系列三(4-硝基苯基)甲烷衍生物2,3和4的几何结构,并计算了其红外光谱和拉曼光谱;通过与实验光谱的对比,对实验光谱中的谱峰进行了指认,并从理论上纠正了部分对3和4红外光谱谱峰不合适的实验指认;同时预测了2,3和4的拉曼光谱.结果表明,几种化合物的振动光谱计算结果与相应的实验结果吻合良好;且化合物2,3和4的拉曼光谱具有相似性.  相似文献   

17.
Data obtained for the kinetics of oxidation of diethyl sulfide (Et2S) by hydrogen peroxide in aqueous solution catalyzed by boric acid indicate that monoperoxoborates B(O2H)(OH) 3 and diperoxoborates B(O2H)2(OH) 2 are the active species. The rates of the reactions of Et2S with B(O2H)(OH) 3 and B(O2H)2(OH) 2 are 2.5 and 100 times greater than with H2O2. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 1, pp. 38–42, January–February, 2007.  相似文献   

18.
The nucleophilic addition of n-butyl- and benzylamines to 1-(4-nitrophenyl)-5H-pyrrolin-5-one and 1-(4-sulfamoylphenyl)-5H-pyrrolin-2-one at 50°C in an excess of the amines with the formation of N-substituted amides of 3-alkyl(benzyl)amino-4-(4-R-anilino)butyric acids was investigated. The N-substituted amides of 3-arylamino-4-hydroxybutyric and 4-hydroxy-2-butenoic acids were synthesized from 2(5H)-furanone and aromatic amines (1:3) at 180°C. 4-Alkylamino-1-(4-nitrophenyl)pyrrolid-2-ones were obtained in the reaction of 1-(4-nitrophenyl)-5-pyrrolin-2-one with ammonia or aliphatic, alicyclic, and aromatic amines (1:3, 90°C, in DMF).  相似文献   

19.
 VOSO4 immobilized within nanoreactors of Al-MCM-41 (VO2+/Al-MCM-41) was synthesized and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption, and chemical analysis techniques. The prepared VO2+/Al-MCM-41 successfully catalyzes the oxidation of aryl alkyl sulfides and up to 99% conversion and 90% selectivity for the corresponding sulfoxides were obtained with H2O2 as oxidant in acetonitrile at room temperature in 30 min.  相似文献   

20.
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