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1.
荧光分析法测定痕量丁二酮   总被引:5,自引:0,他引:5  
本文报道了邻苯二胺与丁二酮在1mol/LH2SO4介质中反应生成2,3-二甲基喹喔啉。该化合物具有较强的荧光(λx/λem=340nm/490nm)其荧光量子产率ΦF=0.101。丁二酮浓度在4.0×10^-7~5.2×10^-5mol/L范围内与转化成产物的相对荧光强度呈线性关系,相对标准偏差为1%,检出限为1.3×10^-7mol/L,考察了30种物质表明,该法选择性好,用于实际啤酒样品中丁二  相似文献   

2.
三氯一茂钛作用下的醛酮再生   总被引:1,自引:0,他引:1  
严世强  陈宁 《合成化学》1996,4(2):184-186
研究了CpTiCl3作用下2-苯基-1,3-二氧杂交戊烷转化的成苯甲醛的反应,在2-苯基-1,3-二氧杂环戊烷:CpTiCl3=1:1反应温度30℃,反应时间6h的最佳条件下,缩醛的转化率达96%,并讨论了不同醛,酮的再生结果以及KI对该转化反应和转化率的影响。  相似文献   

3.
孙绍晖  刘金香 《催化学报》1998,19(5):432-435
研究了反应温度,反应物浓度及空速对乙二胺在H-ZSM-5和K-ZSM-5分子筛催化剂上转化为哌嗪反应的影响。在反应温度为340℃,乙二胺浓度为50%和空速为2.3h^-1条件下,乙二胺在2.6%K-ZSM-5催化剂上的转化率为95%,哌嗪的选择性为965。  相似文献   

4.
从α-蒎烯出发,通过臭氧化,硼氢化钠还原随后用硫酸处理的一锅法,合成了一个新的类四氢呋喃衍生物──2,2-二甲基-3-(反-2-丁烯基)-四氢呋喃3,总收率55.6%。将α-蒎烯(7g,51mmol)的150mL异丙醇溶液冷至-2℃,鼓泡通入含5~6%臭氧的氧气至过量的臭氧从溶液中逸出时止,再通N210min。于0℃将上述溶液滴加至100mL含硼氢化钠(2.54g,65mmol)和氢氧化钠(0.2g,5mmol)的水溶液中,室温下反应6h。减压蒸去100mL溶剂,将残留物2和60%H2SO4(40mL)在80~90℃剧烈搅拌4h,冷却后,混合物用Na2CO3中和,产物用乙醚萃取(3×50mL)。合并醚层,水洗,无水Na2SO4干燥,蒸除溶剂后,收集58.5~61.5℃/400Pa的馏分进行硅胶柱层析(洗脱剂:1%乙酸乙醋/石油醚),得4.4g产物3,总收率达55.6%。  相似文献   

5.
钯-膦-酸体系催化叔丁醇羰化制备异戊酸酯   总被引:1,自引:0,他引:1  
研究了Pd(OAc)2-PPh3-p-Ts催化剂体系存在下,叔丁醇羰化生成异戊酸酯的反应.典型的反应条件是:温度120~160℃,压力3.0~7.0MPa,Pd浓度3.6mmol/L,nPd∶nPPh3∶np-Ts=1∶30∶80,时间12~24h.在上述反应条件下,叔丁醇羰化生成异戊酸酯的产率为11.0%~83.6%,选择性为13.1%~95.0%.  相似文献   

6.
C60的胺加成反应和电喷雾电离质谱(ESI—MS)检测   总被引:2,自引:0,他引:2  
报道了C60与1,3-丙二胺和N,N-二甲基-1,3-丙二胺的加合反应,反应产物未经预先离子化处理直接用ESI-MS进行检测。由于反应产物从甲苯溶液中析出,避免了生成多胺基加合物,产物以单加成物为主。当加合反应在空气氛下进行时,有加合氧的产物C60On(NH2-CH2CH2CH2NR2)m(R=H,CH3)存在。实验发现:N,N-二甲基-1,3-丙二胺比1,3-丙二胺更容易与C60发生多胺基加成和  相似文献   

7.
苯酚氧化羰化合成碳酸二苯酯的新型PdCl2-Co(Pyca)2催化体系   总被引:13,自引:2,他引:13  
研究了新型的Pd-Co催化体系催化氧化碳化苯酚合成碳酸二苯酯。当n(PdCl2):n「Co(Ⅱ)」:n(四丁基化铵):n(苯醌)=1:1:10:25,T=120,P=2.5MPa(Pco/Po2=4:1),反应时间8h,PdCl2-Co(Pyca)2比PdCl2-Co(OAc)2的催化活性高。当使用PdCl2-Co(Pyca)2催化剂时,DPC的产率为6.03%。最佳的反应温度是120℃,DPC的产率随着体系的总压增加而增大,当压力升到3.5MPa时,DPC产率为8.53%。  相似文献   

8.
氮化铁催化剂的制备及其苯胺催化加氢性能   总被引:4,自引:0,他引:4  
用α-Fe2O3与氨气程序升温还原方法制备出不同温度氮气的氮化铁系列催化剂。通过XRD测试对氮化过程中的晶相转变进行了分析。在中压反应装置上考察了氮化铁系列催化剂上苯胺加氢活性以及反应条件对苯胺加氢反应活性的影响。结果表明,在700℃氮化制香的氮化铁催化剂显示有较高的苯胺加氢活性,在氢压为3.0MPa,温度为250℃,n(H2)/n(oil)=18,液体空速(WHSV)为0.3h^-1时,该催化剂  相似文献   

9.
报道了C60与1,3-丙二胺和N,N-二甲基-1,3-丙二胺的加合反应,反应产物未经预先离子化处理直接用ESL-MS进行检测。由于反应产物从甲苯溶液中析出,避免了生成多胺基加合物,产物以单加成物为主。当加合反应在空气氛下进行时,有加合氧的产物C60On(NH2—CH2CH2CH2NR2)m(R=H,CH3)存在。实验发现:N,N-二甲基-1,3-丙二胺比1,3-丙二胺更容易与C60发生多胺基加成和氧加成反应。通过控制反应条件可制备C60二胺的单加成产物。  相似文献   

10.
在不同的温度下,考察了六氰合铁配阴离子「Fe(CN)5」^4-还原trans-「Co(en)2(ImH02」^3+的反应动力学。结果表明,反应遵循H.Taube所提出的外配位界电子传递机理。在25℃,I=0.5mol.L^-1,trans-「Co(en)2(ImH)2」^3+/「Fe(CN)6」^4-反应体系的前驱配合物离子对形成常数为Q1p=98.9mol^-1.L,电子转移速率常数为Km=1.  相似文献   

11.
Collision‐induced dissociation of protonated N ,N ‐dibenzylaniline was investigated by electrospray tandem mass spectrometry. Various fragmentation pathways were dominated by benzyl cation and proton transfer. Benzyl cation transfers from the initial site (nitrogen) to benzylic phenyl or aniline phenyl ring. The benzyl cations transfer to the two different sites, and both result in the benzene loss combined with 1,3‐H shift. In addition, after the benzyl cation transfers to the benzylic phenyl ring, 1,2‐H shift and 1,4‐H shift proceed competitively to trigger the diphenylmethane loss and aniline loss, respectively. Deuterium labeling experiments, substituent labeling experiments and density functional theory calculations were performed to support the proposed benzyl cation and proton transfer mechanism. Overall, this study enriches the knowledge of fragmentation mechanisms of protonated N ‐benzyl compounds. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

12.
Copolymers were synthesized through the chemically oxidative polymerization of N‐ethylaniline (EA) and aniline (AN) in five acid aqueous media. The polymerization yield, intrinsic viscosity, molecular weight, solubility, solvatochromism, electrical conductivity, and mechanical properties of the copolymer films were systematically studied through changes in the comonomer ratio, polymerization temperature, oxidant, oxidant/monomer ratio, and acid medium. Open‐circuit‐potential and temperature measurements of the polymerization solutions showed that the polymerization rate depended on the EA content, and the polymerization was an exothermic reaction. The resultant copolymers were characterized in detail with IR, ultraviolet–visible, and 1H NMR spectroscopy, gel permeation chromatography, wide‐angle X‐ray diffractometry, and scanning electron microscopy. The reactivity ratios of the monomer pair were calculated from the 1H NMR spectra of the copolymers formed at a low conversion. The polymers exhibited good solubility and interesting solvatochromism in most of the solvents and variable conductivity with the EA/AN ratio and doping state. The conductivity of the HCl‐doped copolymers increased monotonically from 5.61 × 10?7 to 2.55 × 10?1 S/cm with decreasing EA content from 100 to 0 mol % and showed a percolation transition between EA concentrations of 20 and 30 mol %. The EA/AN copolymers also had excellent film formability and flexibility together with high mechanical and oxygen‐enriching properties. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6109–6124, 2004  相似文献   

13.
十六烷基三甲基溴化铵相转移催化合成N,N-二乙基苯胺的研究田庆伟(大连铁道学院应用化学系大连116028)关键词十六烷基三甲基溴化铵相转移催化N,N-二乙基苯胺中图分类号0625.631N,N-二乙基苯胺是制备染料、药物和彩色显影剂的重要中间体,用途...  相似文献   

14.
An air‐stable, highly active and versatile method for C─N bond forming reactions is reported. Under mild conditions using a highly reusable support‐free Cu(II)–salen complex, structurally diverse N ‐aryl‐substituted compounds were obtained via direct C─N bond forming reaction of HN‐heterocycles with aryl iodides or three‐component C─N bond forming reaction of 2‐bromobenzaldehyde, aniline derivatives and sodium azide in good to excellent yields. C─N bond forming reaction for benzimidazole derivatives was also performed in the presence of the catalyst under ambient conditions. A series of hybrid benzimidazoles bearing morpholine, tetrazole and quinoxaline backbones were produced using this method. All reactions were performed in short times under air. The Cu(II) catalyst could be reused up to eight times in the direct cross‐coupling reaction of 9H –carbazole with iodobenzene without any decrease in its catalytic activity.  相似文献   

15.
郑柯  林丽丽  冯小明 《化学学报》2012,(17):1785-1790
本工作对手性氮氧–镍络合物催化剂在不对称羰基ene反应中的应用进行了深入研究,通过对配体结构和反应条件的优化,实现了三氟甲基酮酸酯的不对称羰基ene反应.实验发现,氮氧配体的结构对反应对映选择性有很大影响,其中酰胺结构中苯环2,6-位大位阻供电取代基对于反应立体选择性控制起着至关重要的作用.该催化体系有广泛的底物普适性,对一系列α-甲基烯烃都能得到高达80%~96%的收率和97%~>99%ee的对映选择性.同时,通过对照实验以及对催化剂单晶结构的分析,提出了可能的反应过渡态,为该系列催化剂的拓展提供了基础.  相似文献   

16.
黄汉民 《分子催化》2016,30(3):207-213
采用TBHP作为氧化剂,发展了钯催化芳基偶氮化合物N=N双键断裂的氧化羰基化反应.芳基偶氮的羰基化反应在Pd(OAc)2(5%),MeO-BIPHEP (5%),芳基偶氮(0.2 mmol),TBHP(2 equiv),H2O(1 equiv),DCE(1 mL),CO (3.0 MPa)的条件下110℃反应12h后,经柱层析纯化分离得到31%-91%的芳基脲.初步的机理研究表明,芳基偶氮化合物的N=N双键断裂原位产生芳基胺,再进一步氧化羰基化生成芳基脲.  相似文献   

17.
X-ray analysis has revealed that N,N,N′,N′-tetramethyl-ethylenediamine 1 form donor–acceptor complex 3 with 1-bromo-2-iodo-tetrafluoroethane 2, in which the N X (X = Br, I) distances are longer than the average covalent bond length between X and N, but are also definitively shorter than the sum of the corresponding van der Waals radii of X and N, thus that indicating weak interactions between the nitrogen and bromine or iodine atoms. In our experimental section, a valuable method for recrystallization and collect X-ray data from crystals that easily exhibit decay and can be cracked is reported.  相似文献   

18.
A series of new mixed ligand hexacoordinated ruthenium(III) Schiff base complexes of the type [RuX(2)(EPh(3))(2)(LL')] (X=Cl, E=P; X=Cl or Br, E=As and LL'=anion of the Schiff bases derived from the condensation of 2-hydroxy-1-naphthaldehyde with aniline, 4-chloroaniline, 2-methyl aniline and 4-methoxy aniline) are reported. All the complexes have been characterized by analytical and spectral (IR, electronic and EPR) data. The redox behavior of the complexes has also been studied. The complexes exhibit catalytic activity in the oxidation of benzyl alcohol to benzaldehyde in the presence of N-methyl morpholine-N-oxide (NMO). An octahedral structure has been proposed for all of the complexes.  相似文献   

19.
Towards the aim of creating a functional mimic of isopenicillin N synthase, a small molecule designed to coordinate around iron(II) and model the enzyme active site has been prepared in nine synthetic steps from 2,6-bis(hydroxymethyl)pyridine, (S)-(+)-mandelic acid and pivaldehyde. One aspartate, two histidines and a water ligand in the natural enzyme are replaced by an α-hydroxy acid, pyridine and aniline in the model compound. Additionally, a free thiol designed to simulate the enzyme substrate, δ-(l-α-aminoadipoyl)-l-cysteinyl-d-valine, is linked to the ligand by a three carbon chain. We postulate that in the presence of molecular oxygen, the complex formed between this synthetic ligand and iron(II) will display oxidative chemistry similar to that observed in the active site of isopenicillin N synthase.  相似文献   

20.
Four new hetero- and homo-leptic iridium(III) bisterpyridine complexes have been prepared which incorporate aniline (tpy-φ-NH(2)), benzoic acid (tpy-φ-COOH), and benzyl alcohol (tpy-φ-CH(2)OH) substituents at the 4' positions of the tpy ligands (tpy = 2,2':6',2'-terpyridine, φ = phenylene). The electrochemical behaviour and ground and excited state spectroscopic properties of the complexes are reported, and the X-ray crystal structures of a homoleptic benzyl alcohol [Ir(tpy-φ-CH(2)OH)(2)](PF(6))(3), homoleptic aniline [Ir(tpy-φ-NH(2))(2)](PF(6))(3), and heteroleptic benzyl alcohol/aniline substituted complex [Ir(tpy-φ-CH(2)OH)(tpy-φ-NH(2))](PF(6))(3) have been solved. Complexes with aniline substituents were found to display absorption bands at around 430 nm corresponding to intraligand charge transfer (ILCT) that are sensitive to changes in solvent and pH. Strong emission in the visible region involving the ILCT state is observed in two of the complexes (Φ(e) = 0.7% and 2.6%) in acetonitrile. In the heteroleptic aniline/benzyl alcohol complex the Stokes shift is shown to be linearly related to solvent polarisability according to the Lippert equation, but only for solvents with weak hydrogen bonding interactions. Additionally, in water, emission from the ILCT state is quenched and only weak ligand centred (LC) emission is observed. The long lifetimes and quantum yields of these complexes make them interesting candidates for probes in sensing applications, especially [Ir(tpy-φ-CH(2)OH)(tpy-φ-NH(2))(2)](PF(6))(3) due to its unusual sensitivity to the solvent environment.  相似文献   

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