醚的初始暗氧化反应机理的研究

有机化合物的空气氧化是一个历史悠久的研究课题。早在1851年Schonbein[1]就注意到醚在空气中会被氧化产生过氧化物。本世纪初,Clover和Milas分析了醚的空气氧化产物,并且对醚的氧化机理,进行了研究。     

Some reactions of polyfluoroalkyl ethers and the preparation of bis(trifluorovinyl) ether

d1 and meso Bis (1,2,2-trifluoroethyl) ether and 1,1,2,2 tetrafluoroethyl 1,1,2-trifluoroethyl ether with aluminium halides or boron trichloride yield halogenopolyfluoroalkyl ethers. The epimerisation of the d1 and meso stereoisomers is discussed. Chlorination of bis (1,2,2-trifluoroethyl) ether and 1,1,2,2-tetrafluoroethyl 1,2,2-trifluoroethyl ether gives new chloropolyfluorodiethyl ethers and from bis (1,2-dichlorotrifluoroethyl) ether, bis (trifluorovinyl) ether is obtained by dechlorination.     

Synthesis and Cation Recognition Study of Novel Benzo Crown Ether Functionalized Enamine Derivatives

A novel series of benzo crown ether (dibenzo 18-crown-6 ether, benzo 18-crown-6 ether, and benzo 15-crown-5 ether) functionalized enamines derivatives from amino benzo crown ether (4-amino dibenzo 18-crown-6 ether, 4-amino benzo 18-crown-6 ether, 4-amino benzo 15-crown-5 ether) and substituted 3-(dimethylamino)-1-phenylprop-2-en-1-one compounds have been synthesized. All the synthesized compounds were characterized by infrared, ¹H NMR, ¹³C NMR, distortionless enhancement polarization transfer, and mass and elemental analysis techniques. The cation recognition property for benzo crown ether enamine 8a was studied by absorption and fluorescence spectroscopy.     

Liquid–Liquid Equilibria of Oxygenate Fuel Additives with Water at 25°C: Ternary and Quaternary Aqueous Systems of Methyl tert-Butyl Ether and tert-Amyl Methyl Ether with Methanol or Ethanol

Experimental tie-line data have been determined for the ternary system water + methyl tert-butyl ether + tert-amyl methyl ether and the quaternary systems water + methanol + methyl tert-butyl ether + tert-amyl methyl ether, and water + ethanol + methyl tert-butyl ether + tert-amyl methyl ether at 25°C and ambient pressure. The experimental results have been satisfactorily correlated using the modified UNIQUAC and extended UNIQUAC models with ternary and quaternary, in addition to binary parameters.     

Skeletal rearrangements of protonated molecular ions of some ethers

Skeletal rearrangements are reported of protonated molecular ions in the chemical ionization mass spectra of allyl cyclohexyl ether, benzyl cyclohexyl ether, t-butyl cyclohexyl ether and dibenzyl ether.     

Novel photocurable monomers: The synthesis of difunctional vinyl ethers with a phosphonate group and difunctional 1‐propenyl ethers with a phosphonate group and their photoinitiated cationic polymerization

Phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were prepared by the regioselective addition reaction of glycidyl vinyl ether (GVE) or 1‐propenyl glycidyl ether with diaryl phosphonates with quaternary onium salts as catalysts. The reaction of GVE with bis(4‐chlorophenyl) phenylphosphonate gave bis[1‐(4‐chlorophenoxy methyl)‐2‐(vinyloxy)ethyl]phenylphosphonate in a 68% yield. The structures of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were confirmed by IR and ¹H NMR spectra and elemental analysis. Photoinitiated cationic polymerizations of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were investigated with photoacid generators. The polymerization of vinyl ether groups and 1‐propenyl ether groups of the obtained monomers proceeded very smoothly with a sulfonium‐type cationic photoinitiator, bis[4‐(diphenylsulfonio)phenyl]sulfide‐bis(hexafluorophosphate), upon UV irradiation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3105–3115, 2005     

可控交联聚醚醚酮的动态力学性能

动态力学分析技术(DMA)是研究聚合物性能的重要方法之一．动态力学实验可以检测聚合物的玻璃化转变温度和次级松弛过程,直接与聚合物的链结构和聚集态结构密切相关,聚合物的化学组成、支化和交联、结晶和取向、增塑和共混等结构因素的变化,都与分子运动状态的变化密切相关,而分子运动的变化又能灵敏地反映在动态力学性能上,     

Study on dynamics characteristics of wet air oxidation of non-ionic surfactants

Wet air oxidation is an effective method to deal with highly concentrated nondegradable emulsification wastewater which contains non-ionic surfactants. This article illustrates our investigation on dynamic characteristics of wet air oxidation of typical non-ionic surfactants like polyether, phenol ether and widely used alcohol ether. The experimental results indicated that the oxidation rate of polyether, phenol ether and alcohol ether obviously ascended as the temperature rose. A good oxidation effect was available at 240℃. The TOC removal rate could reach 88.0%, 94% and 91.5%, after 125 min reaction. Alcohol ether was prone to an easier oxidation compared with polyether and phenol ether when the temperature was 220℃ or below. The oxidation rate of alcohol ether was higher than that of polyether at 160℃, while the oxidation rate of polyether was higher than that of phenol ether between 180℃ and 220℃. During the later period of the reaction at 240℃, the rate of phenol ether was higher than that of alcohol ether, which was still higher than that of polyether. Partitioned first order kinetics model analy-sis showed that the apparent activation energy of alcohol ether was lower than that of both polyether and phenol ether in the leading stage and lagging stage, and it was easy to acquire a higher oxidation rate for alcohol ether at low temperature. Three parameter general dynamics model analyses showed that the reason why the oxidation rate of polyether was lower than that of alcohol ether was that the oxidation of polyether was more apt to be converted to intermediate production than that of alcohol ether, whereas between 200℃ and 220℃, the direct oxidation rate of polyether and the oxidation rate of intermediate product were obviously lower than that of alcohol ether. The apparent activation energy of direct and indirect oxidation of polyether was 43.37 and 60.45 kJ?mol?1, respectively, while the corre-sponding apparent activation energy of alcohol was 38.74 and 58.09 kJ·mol?1, respectively.     

Applications of Fourier Transform Raman spectroscopy in the synthetic polymer field

The application of FT Raman spectroscopy in the study of a wide range of polymer systems is discussed. The following have been included to give the reader an insight into the variety of areas which can successfully be studied using this important technique: the problem of crystallinity; nylons; poly(aryl ether ketone) and poly(aryl ether ether ketone); poly(aryl ether ether sulphone) and poly(aryl ether sulphone); epoxy resin curing; copolymers; copolymers of tetrafluoroethylene and hexafluoropropylene; polythioethers; and gels.     

Measurement of fuel oxygenates in tap water using solid-phase microextraction gas chromatography-mass spectrometry

The presence of alkyl ether fuel oxygenates in drinking water supplies has raised public health concerns because of possible adverse health effects from chronic exposure to these compounds. To enable large exposure studies exploring possible relationships between chronic exposure to alkyl ether fuel oxygenates and health effects, we developed an improved analytical method, using headspace solid-phase microextraction coupled with capillary gas chromatography and mass spectrometry. This method quantifies trace levels of methyl tertiary-butyl ether, ethyl tertiary-butyl ether, di-isopropyl ether, and tertiary-amyl methyl ether in tap water. The method achieves detection limits of less than 0.025 microg/L for all analytes and linear ranges of three orders of magnitude in the measurement of the alkyl ether fuel oxygenates in 5-mL tap water samples. The relative percentage of recoveries of the alkyl ether fuel oxygenates ranged from 97% to 105%. The relative standard deviation ranged from 2% to 6%. Methyl tertiary-butyl ether was detected in samples of tap water taken from geographically diverse regions of the United States. The improved throughput and sensitivity of this method will enable large epidemiologic field studies of the prevalence and magnitude of exposure to alkyl ether fuel oxygenates in the general population.     

13C nuclear magnetic resonance studies on the stereochemical configurations of 2,4-dimethoxypentane and poly(alkyl vinyl ethers)

¹³C nuclear magnetic resonance (CMR) spectra were obtained for 2,4-dimethoxypentane, which is a model compound of poly(methyl vinyl ether), and the effects of the solvent and temperature on the chemical shifts were investigated. CMR spectra of poly-(alkyl vinyl ethers) were also determined and analyzed. The diad tacticities were obtained from β-methylene carbon resonances of poly(methyl vinyl ether), poly(ethyl vinyl ether), and poly(isobutyl vinyl ether), but not from those of poly(isopropyl vinyl ether) and poly(tert-butyl vinyl ether). The methoxyl carbon resonance of poly(methyl vinyl ether) and the ethoxyl methylene carbon resonance of poly(ethyl vinyl ether) showed splittings corresponding to pentad and triad sequences, respectively. The α-methine and quaternary carbon resonances of poly(tert-butyl vinyl ether) showed splittings corresponding to pentad and triad sequences, respectively.     

Acyl Iodides in Organic Synthesis: VI. Reactions with Vinyl Ethers

Reactions of acetyl iodide with butyl vinyl ether, 1,2-divinyloxyethane, phenyl vinyl ether, 1,4-di-vinyloxybenzene, and divinyl ether were studied. Vinyl ethers derived from aliphatic alcohols (butyl vinyl ether and 1,2-divinyloxyethane) react with acetyl iodide in a way similar to ethyl vinyl ether, i.e., with cleavage of both O–Csp2 and Alk–O ether bonds. From butyl vinyl ether, a mixture of vinyl iodide, butyl acetate, vinyl acetate, and butyl iodide is formed, while 1,2-divinyloxyethane gives rise to vinyl iodide, vinyl acetate, and 2-iodoethyl acetate. The reaction of acetyl iodide with divinyl ether involves cleavage of only one O–Csp2 bond, yielding vinyl acetate and vinyl iodide. In the reactions of acetyl iodide with phenyl vinyl ether and 1,4-divinyloxybenzene, only the O–CVin bond is cleaved, whereas the O–CAr bond remains intact.     

Potassium-selective PVC membrane electrodes based on bis- and poly(crown ether)s

Potassium-selective PVC membrane electrodes based on bis- and poly (crown ether)s containing benzo-15-crown-5 moiety as neutral carrier were prepared and selectivity coefficients for various monovalent ions were measured in order to elucidate the effect of complexing property of these crown ether derivatives on the electrode response. In the preference for potassium over sodium of the electrodes, these bis- and poly (crown ether)s were found to exceed the corresponding monocyclic crown ether considerably, which reflects the easy complexation of stable 2:1 complexes of crown ether ring and ion, derived from the cooperative effect of two adjacent crown ether rings.     

Synthesis of cyanine dyes derived from benzotellurazo‐15‐crown‐5

A series of crown ether cyanine dyes including crown ether styryl cyanine dyes, crown ether merocyanine dyes and crown ether squarylium cyanine dyes (unsymmetric and symmetric) derived from key intermediate 2‐methyl‐5,6(15‐crown‐5)benzotellurazole ( 1 ) were prepared.     

Cleavage of different ether bonds in butyl glycidyl ether and allyl glycidyl ether by K, K(15-crown-5)2

The kind of substituent in alkyl glycidyl ethers affects the course of their reaction with K⁻, K⁺(15-crown-5)₂. The cyclic oxirane ring is exclusively cleaved in the case of butyl glycidyl ether whereas the presence of the unsaturated allyl group in the glycidyl ether molecule unexpectedly prefers the scission of the linear ether bond. In both the systems organometallic intermediates are formed. They react with crown ether causing its ring opening. Allylpotassium formed from allyl glycidyl ether reacts also with another glycidyl ether molecule; the oxirane ring is opened in this case.     

Simultaneous determination of NOGE-related and BADGE-related compounds in canned food by ultra-performance liquid chromatography–tandem mass spectrometry

An improved analytical method enabling rapid and accurate determination and identification of bisphenol F diglycidyl ether (novolac glycidyl ether 2-ring), novolac glycidyl ether 3-ring, novolac glycidyl ether 4-ring, novolac glycidyl ether 5-ring, novolac glycidyl ether 6-ring, bisphenol A diglycidyl ether, bisphenol A (2,3-dihydroxypropyl) glycidyl ether, bisphenol A (3-chloro-2-hydroxypropyl) glycidyl ether, bisphenol A bis(3-chloro-2-hydroxypropyl) ether, and bisphenol A (3-chloro-2-hydroxypropyl) (2,3-dihydroxypropyl) ether in canned food and their contact packaging materials has been developed by using, for the first time, ultra-performance liquid chromatography coupled with tandem mass spectrometry. After comparison of electrospray ionization and atmospheric pressure chemical ionization in positive and negative-ion modes, tandem mass spectrometry with positive electrospray ionization was chosen to carry out selective multiple reaction monitoring analysis of novolac glycidyl ethers, bisphenol A diglycidyl ether, and its derivatives. The analysis time is only 5.5 min per run. Limits of detection varied from 0.01 to 0.20 ng g(-1) for the different target compounds on the basis of a signal-to-noise ratio (S/N) = 3; limits of quantitation were from 0.03 to 0.66 ng g(-1). The relative standard deviation for repeatability was <8.01%. Analytical recovery ranged from 87.60 to 108.93%. This method was successfully applied to twenty samples of canned food and their contact packaging materials for determination of migration of NOGE, BADGE, and their derivatives from can coatings into food.     

Gas-phase reactions of brominated diphenyl ethers with OH radicals

A small volume reaction chamber coupled to a mass spectrometer was used to study the gas-phase kinetics and mechanism of the reaction of OH radicals with diphenyl ether and seven polybrominated diphenyl ethers (PBDEs) with 1-2 bromines. Relative rate constants for these reactions were determined using isopropyl nitrite photolysis in He-air mixtures at approximately 740 Torr between the temperatures of 326-388 K. The Arrhenius expression for each compound was used to extrapolate the following OH rate constants at 298 K (in units of 10(-12) cm3 molecule(-1) s(-1), with 95% confidence intervals): diphenyl ether, 7.45 +/- 0.13; 2-bromodiphenyl ether, 4.7; 3-bromodiphenyl ether, 4.6; 4-bromodiphenyl ether, 5.7; 2,2'-dibromodiphenyl ether, 1.3; 2,4-dibromodiphenyl ether, 3.8; 3,3-dibromodiphenyl ether, 3.2; and 4,4'-bromodiphenyl ether, 5.1. The measured OH rate constants are in reasonable agreement with those predicted by structure activity relationships. Positive temperature dependences of these OH rate constants are observed for all compounds measured except for diphenyl ether and 4,4'-dibromodiphenyl ether. Bromophenols (in yields up to 20% relative to the amount of PBDE consumed) and Br2 were characterized as products of these reactions, suggesting that OH addition to ipso positions of these brominated aryls may be an important reaction pathway.     

聚合物冠醚的合成与性能——Ⅶ.梳形聚醚的合成及络合、催化性能

近年来通过非冠醚单体的聚合以合成聚合物冠醚,国内外都有一些新的进展.环氧化合物开环聚合时可得到具有乙撑氧链的聚醚,我们选用含环氧基团的化合物作为聚合单体,同时在环氧基团上又引入另外的乙撑氧链,经过开环聚合得到相应的梳形聚醚的主链和侧链都含有乙撑氧链,具有开链冠醚的结构特点,尚未见报道.     

Synthesis and Adsorption Property of Dihydroxyl Azacrown Ether—Grafted Chitosan

A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan. The adsorption property of the azacrown ether chitosan for Pb^2 , Cr^3 , and Ag^ , were determined. The experimental results showed that the dihydroxyl azacrown ether grafted chitosan has high adsorption capacity and high selectivity for some metal ions.     

Electrochemical fluorination of chlorine-containing ethers

The electrochemical fluorination of chlorine-containing ethers has been studied. In general, it was found that a chlorine bonded to an a-carbon atom in the ethers was readily removed during electrochemical reaction in anhydrous hydrogen fluoride, whilst a chlorine bonded to the β-carbon atom was retained to yield β-chlorinated polyfluoroethers.Through the use of this method, several new chloropolyfluoroethers, e.g. 2-chloro-1,1,2,2-tetrafluoroethyl difluoromethyl ether, 2,2-dichloro-1,1,2-trifluoroethyl trifluoromethyl ether 2,2-dichloro-1,1,2-trifluoroethyl difluoromethyl ether, 2,2-dichloro-1,1,2-trifluoroethyl chlorodifluoromethyl ether, 2-chloro-1,1,2,2-tetrafluoroethyl chlorodifluoromethyl ether and 2,2-trichloro-1,1-difluoroethyl trifluoromethyl ether, have isolated and characterized.