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1.
几种新的3,7-二取代二苯并五元环状溴嗡盐的合成   总被引:3,自引:1,他引:2  
侯自杰 《化学学报》1995,53(1):94-97
4,4'-二硝基联苯在浓硫酸中与溴化钠及过硫酸钾反应,直接生成3,7-二硝基二苯并溴五环盐(5).5经SnCI~2-HCI还原得到3,7-二氨基二苯并溴五环盐(6),由6制得重氮盐溶液分别与氯化亚铜,溴化亚铜及碘化钾反应得到3,7-二氯二苯并溴五环盐(7),3,7-二溴二苯并溴五环盐(8)及3,7-二碘二苯并溴五环盐(9).5-9均匀新化合物,其结构经^1HNMR.MS.IR证实.  相似文献   

2.
《Analytical letters》2012,45(9):1016-1027
Stereoisomers of long-chain secondary alcohols are used as sex pheromone precursors among pine sawflies and some species can be severe pine forest pests. To use their pheromone in environmentally friendly pest management, methods are needed that can determine the stereochemistry of the precursor alcohols. Combinations of 11 acid chloride derivatives and 10 GC columns were evaluated for separation of stereoisomers of 3,7-dimethylundecan-2-ol, 3,7-dimethyldodecan-2-ol, 3,7-dimethyltridecan-2-ol, 3,7-dimethyltetradecan-2-ol, and 3,7-dimethylpentadecan-2-ol. Derivatization with (S)-2-acetoxypropionyl chloride in combination with a Chiraldex B-PA column separated all eight stereoisomers of 3,7-dimethylundecan-2-ol, 3,7-dimethyldodecan-2-ol, and 3,7-dimethyltridecan-2-ol. A combination of two different derivatization methods was needed to separate all stereoisomers of the longer chained alcohols 3,7-dimethyltetradecan-2-ol and 3,7-dimethylpentadecan-2-ol. A female extract of the pine sawfly Neodiprion lecontei was also analyzed and the stereochemistry of the sex pheromone alcohol precursor was determined to be (2S,3S,7S)-3,7-dimethylpentadecan-2-ol at an amount of about 7 ng/female. This paper presents the first GC-MS separation of all eight stereoisomers of 3,7-dimethylundecan-2-ol, 3,7-dimethyldodecan-2-ol, and 3,7-dimethyltridecan-2-ol in a single analytical run and also the first GC-MS determination of the stereochemistry of the sex pheromone precursor found in females of N. lecontei.  相似文献   

3.
《Analytical letters》2012,45(7):395-402
Abstract

Use of the new, solid-membrane cupric electrode for non-aqueous titrations, a significant advancement over the earlier liquid-membrane electrode, is illustrated. The solid-membrane cupric electrode was used for the complexometric titration of cupric ion with several ligands in methanol, acetone and acetonitrile.  相似文献   

4.
陆绍荣 《化学研究》1999,10(2):35-37
溴化铜的溴代反应结果表明:在反应温度为60℃,原料的摩尔配比为4-氨基-3,5-二氯苯乙酮∶溴化铜=1∶2,反应2.2h合成标题化合物,溴代产率可达95%以上  相似文献   

5.
In this paper, cupric oxides was found to effectively oxidize levulinic acid (LA) and lead to the decarboxylation of levulinic acid to 2-butanone. The effects of cupric oxide dosage, reaction time and initial pH value were investigated in batch experiments and a plausible mechanism was proposed. The results showed that LA decarboxylation over cupric oxides at around 300 °C under acidic conditions produced the highest yield of butanone (67.5%). In order to elucidate the catalytic activity of cupric oxides, XRD, AFM, XPS and H(2)-TPR techniques was applied to examine their molecular surfaces and their effects on the reaction process.  相似文献   

6.
The cupric sulfate–hydrazine system has been used to initiate the aqueous solution polymerization of methyl methacrylate at pH 9.25 in the presence of oxygen. At cupric sulfate concentrations greater than the saturation solubility of cupric hydroxide, hydrazine is adsorbed on, and decomposes on, the surface of the hydroxide. The kinetics of the decomposition are zero-order both in the absence and the presence of monomer. The initiation of the polymerization occurs both at the surface of the cupric hydroxide on to which some monomer is adsorbed and also in solution. Below the saturation solubility of cupric hydroxide, the initiation reaction between cupric ions and hydrazine occurs in solution.  相似文献   

7.
The polymerization of methyl methacrylate with cupric laurate in combination with N,N-dimethyl formamide as initiator was studied in carbon tetrachloride medium at 60°C. The rate of polymerization was found to be proportional to the 3/2th power of the monomer concentrations and to the square root of both cupric laurate and DMF concentrations. Spectroscopic investigations indicated a ternary complex formation involving cupric ion, methyl methacrylate, and DMF. A reaction scheme is suggested on the basis of these results and various kinetic constants have been evaluated.  相似文献   

8.
The aqueous polymerization of methyl methacrylate (MMA) with sodium bisulfite as initiator was carried out in a nitrogen atmosphere with and without inorganic substances like copper metal, cupric and cuprous oxides, and cupric sulfide. It was also done in the presence of organocopper compounds like copper phthalocyanine and copper biphthalocyanine. The catalytic effect of these compounds was studied. Mildly heated cupric sulfide proved to have a small catalytic effect on the polymerization process that may be attributed to the retarding effect of the released elementary sulfur. The catalytic effect of the different copper compounds and the copper metal equivalent contained in them was studied. The polymerization process revealed that cuprous and cupric oxides possess the highest catalytic influence. An attempt was made to investigate the role of the different anions on the polymerization process. It was found that an increase on the concentration of the copper compounds leads to a corresponding increase in the catalytic effect. It was also observed that the behavior of insoluble copper catalysts is different from that of the soluble. The effect of these catalysts on the average molecular weight of the poly(methyl methacrylate) (PMMA) produced was also examined.  相似文献   

9.
铜及氧化铜对煤燃烧过程多环芳烃排放的影响   总被引:3,自引:1,他引:3  
在实验管式炉上研究了金属铜和氧化铜对烟煤燃烧过程中PAHs生成的影响。采用气相色谱分析PAHs。实验结果表明,铜会促进PAHs的生成,而且主要是促进中高分子量PAHs的生成,这是由于铜为PAHs的合成提供了大量的活性反应中心。另一方面氧化铜对PAHs的合成和裂解具有双重催化效果,从而显著增加了中分子量PAHs的排放。在800 ℃以下,添加铜和氧化铜都减小了PAHs排放的毒性当量。在900 ℃以上,添加铜增大了PAHs排放的毒性当量。添加氧化铜时与添加铜时的规律类似,但是在1100℃以上,PAHs排放的毒性当量要比不添加时小。  相似文献   

10.
溴化铜的溴代反应结果表明:在反应温度为60℃,原料的摩尔配比为4-氨基-3,5-二氯苯乙酮∶溴化铜=1∶2,反应2.2h合成标题化合物,溴代产率可达95%以上  相似文献   

11.
The polymerization of methyl methacrylate initiated by cupric laurate in combination with benzoin has been investigated in carbon tetrachloride medium at 60°C. The rate of polymerization was found to be proportional to the square root of both cupric ion and benzoin concentrations, and to the 1.5th power of the monomer concentration. Spectral studies indicated that there is a complex formation between cupric ion and the monomer methyl methacrylate. A reaction scheme, based on initial formation of the complex and its subsequent reaction with benzoin to produce the free radicals responsible for initiation has been postulated to explain the observed results.  相似文献   

12.
铜(Ⅱ)及其配合物催化胆红素氧化动力学的研究   总被引:2,自引:0,他引:2       下载免费PDF全文
本文用电化学,吸收光谱等方法对Cu(2+)及其配合物与胆红素在碱性(pH10)条件下的作用规律进行了研究.发现Cu(2+)及其配合物对胆红素的氧化的催化作用依配合物的稳定性和配体齿数不同而异.在胆红素的氧化过程中,真正起氧化作用的是溶解氧.  相似文献   

13.
Copper proteins involving either isolated centres (horse liver alcohol dehydrogenase with Cu(II) at the active site, cupric complex of BSA and porcine ceruloplasmin) or binuclear cuprous (Limulus polyphemus deoxyhemocyanin, Cu(I) complex with disulphides in BSA) or cupric sites (Limulus deoxymethemocyanin) were studied by means of DPP in buffered media. The reduction of the binuclear sites was directly observable in the polarograms. The reduction responses of the isolated cupric centres were promoted either by EDTA or in a weakly acidic buffered medium at pH 5.4 to 5.6. Electroactive ternary complexes (e.g. Cu(II): protein: EDTA) permitting a bridged electron transfer are proposed to be the key intermediates in the promoted electroreduction of cupric centres.  相似文献   

14.
A single glass capillary nanopore-based sensing platform for rapid and selective detection of cupric ions is demonstrated by utilizing polyglutamic acid (PGA) as a non-immobilized probe. The detection is based on the significant decrease of ionic current through nanopore and the reversal of ion current rectification responses induced by the chelated cupric ions on the probes when in the presence of cupric ions. PGA shows high selectivity for detecting cupric ions rather than other metal ions. The sensitivity of the sensing platform can be improved about 1–2 orders of magnitude by employing asymmetric salt gradients during the measurements. And the PGA-based nanopore sensing platform shows excellent regenerability for Cu2+ sensing applications. In addition, the method is found effective and reliable for the detection of cupric ions in real samples with small volume down to 20 μL. This nanopore-based sensing platform will find promising practical applications for the detection of cupric ions.  相似文献   

15.
The generation of the new functionalized and highly pyramidalized alkenes, 3,7-(2,2'-biphenylene)tricyclo[3.3.0.0(3,7)]oct-1(5)-ene (20) and 3,7-sulfonyldioxytricyclo[3.3.0.0(3,7)]oct-1(5)-ene (39), and their trapping with 1,3-diphenylisobenzofuran and 11,12-dimethylene-9,10-dihydro-9,10-ethanoanthracene are described. While both alkenes 20 and 39 failed to give the expected cyclobutane or diene dimers, 20 was reacted with 3,7-dimethyltricyclo[3.3.0.0(3,7)]oct-1(5)-ene (1b) to give the cross-coupled product 4,5-(2,2')-biphenylene-10,11-dimethylpentacyclo[8.2.1.1(2,5).1(4,7).1(8,11)]hexadeca-1,7-diene (33). DFT calculations [B3LYP/6-31G(d)] on compound 20 gave important parameters of this pyramidalized alkene, such as the pyramidalization angle (61.7 degrees), the strain energy (72.9 kcal/mol), and the HOMO/LUMO gap (3.79 eV).  相似文献   

16.
三元P-Cu-W杂多阴离子柱撑水滑石的制备   总被引:2,自引:0,他引:2  
用微波法制备了杂多阴离子柱撑水滑石,经XRD、IR、ESR和DTA表征,证明制备的样品具有良好的层柱结构,其热稳定性比相应的杂多酸盐提高约40℃,杂多阴离子中Cu2+并非处于标准的八面体场中,而是处于一种近似于五配位的立方锥场,并随嵌入层间后更趋于五配位。  相似文献   

17.
We describe a novel approach for the synthesis of a series of 3,7-difunctionalised symmetric and unsymmetrical analogues of the tricyclic antidepressant (TCA) imipramine, which uses a key palladium-catalysed amination/cyclisation of an ester-functionalised dibromide. Of the ester, methyl, hydroxymethyl and methoxymethyl disubstituted compounds prepared, 3,7-dimethyl-imipramine was found to be the most potent against the human serotonin transporter (hSERT). The inhibitory potency of 3,7-dimethyl imipramine was found to be at least as high as the parent imipramine. This novel TCA also exhibits an increased selectivity (relative to imipramine) in binding to hSERT versus the human norepinephrine transporter (hNET). Even higher selectivity could be obtained with 3,7-dihydroxymethyl imipramine, which was found to be 167-fold more selective for hSERT over hNET, representative of a 120-fold gain in selectivity relative to the parent imipramine. These results further validate our previous model for the binding of imipramine and high-affinity analogues of imipramine to the central binding site of hSERT.  相似文献   

18.
将氯化重氮苯的溶液加入氯化汞、维生素C、丙酮和少量氯化铜的混合物中,得到80%的氯化苯汞;如在反应混合物中补加维生素C、氯化铜和浓氨水,则得到二苯汞。用同样的方法制备了其他的二芳基汞,并讨论了反应可能的机理。  相似文献   

19.
Hoyer B 《Talanta》1991,38(1):115-118
It is shown that near-Nernstian calibration slopes can be obtained with a Cu(1.8)Se electrode in a range of cupric ion buffers in spite of a high chloride content. Best results are obtained with the ligands ethylenediamine, glycine and histidine. The onset of cupric ion toxicity towards marine organisms falls within the pCu calibration range obtained with glycine, and the Cu(1.8)Se electrode could, therefore, be useful for monitoring cupric ion activity in bioassays in sea-water media.  相似文献   

20.
The reactions of diamines and polyamines with cupric ion were investigated potentiometrically, using a copper ion-selective indicator electrode and a single-junction reference electrode. In general, cupric ion reacted with 2 mol of vic-diamines or their salts. Tetraaza compounds reacted on an equimolar basis with Cu(II). Both vic-diamines and their salts, as well as tetraaza compounds, could be titrated in the presence of excess ammonia. With cupric ion in ammoniacal solution these compounds yield a characteristic purple/violet color. Diamines separated by more than two methylene groups cannot be determined in the presence of ammonia and yield a blue color. Diamines with more than four methylene groups react with cupric ion on an equimolar basis, also yielding a blue color.  相似文献   

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