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61.
Moores A Mézailles N Ricard L Mathey F Le Floch P 《Chemical communications (Cambridge, England)》2003,(15):1914-1915
Reaction of a tetraphenyl-1,2-diphosphinyl dianion with [FeCl2(THF)1.5] or [Ru(COD)(acac)2] yields dianionic complexes which further react with Ph3SnCl to afford the corresponding bis(1,4-diphosphabutadiene) complexes. 相似文献
62.
63.
Novel polyesteramide-based di- and triblock copolymers: From thermo-mechanical properties to hydrolytic degradation 总被引:1,自引:0,他引:1
Gaëlle Deshayes Cécile Delcourt Ingrid Verbruggen Lise Trouillet-Fonti Franck Touraud Etienne Fleury Philippe Degée Mathias Destarac Rudolph Willem Philippe Dubois 《European Polymer Journal》2011,(1):98-110
Two types of biodegradable poly(ε-caprolactone (CLo))-co-poly(ε-caprolactam (CLa)) copolymers were prepared by catalyzed hydrolytic ring-opening polymerization. For the first type of materials, the respective cyclic comonomers were added simultaneously in the reaction medium leading to the formation of copolymers having a random distribution of co-units within the polyesteramide sequence, as evidenced by 1H and 13C NMR. For the second type of copolymers, the cyclic comonomers were added sequentially in the reaction medium yielding diblock polyesteramides, again evidenced by NMR. The thermal and thermo-mechanical properties of the copolymers were investigated by DSC and DMA and correlated with the copolymer topology and composition. The copolymers were characterized by a storage modulus and α transition temperature intermediate to the modulus and Tg of the corresponding homopolymers. The chemical composition and molecular weight of the copolymers proved to have only a limited effect on the thermo-mechanical properties of the materials. The hydrolytic degradation of random copolymers was studied in a phosphate buffer at 60 °C and discussed in terms of chemical composition and molecular weight of the copolymers. 相似文献
64.
Audrey Hecka Benoît Maunit Frédéric Aubriet Jean‐François Muller 《Rapid communications in mass spectrometry : RCM》2009,23(6):885-898
Five well‐known active naphtodianthrone constituents of Hypericum perforatum (St John's Wort) extracts have been investigated by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI‐FTICRMS) and ESI‐FTICRMSn. The studied compounds were hypericin, pseudohypericin, protohypericin, protopseudohypericin (biosynthetic precursors of the two former compounds, respectively) and isopseudohypericin (alkaline degradation product of pseudohypericin). Dissociation mass spectrometry measurements performed on the [M–H]? ion presented a variable efficiency as a function of the used activation mode. Sustained off‐resonance irradiation collision‐induced dissociation (SORI–CID) only led to a restricted number of fragment ions. In contrast, IRMPD ensured the detection of numerous product ions. Ions detected in ESI‐FTICRMS and ESI‐FTICRMSn experiments were measured with a very high mass accuracy (typically mass error is lower than 0.5 mDa at m/z close to 500) that allowed unambiguous formulae to be assigned to each signal observed in a mass spectrum. In spite of similar structures, specific fragmentation patterns were observed for the different compounds investigated. This study may be useful in the future to characterize in natural extracts these compounds (or derivatives of these compounds) by liquid chromatography/tandem mass spectrometry (LC/MS/MS) experiments by considering the MS/MS transitions highlighted in this paper. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
65.
F. Hubert J. P. Dufour R. Del Moral A. Fleury D. Jean M. S. Pravikoff H. Delagrange H. Geissel K. -H. Schmidt E. Hanelt 《Zeitschrift für Physik A Hadrons and Nuclei》1989,333(3):237-246
The beta-gamma spectroscopic study of22O is presented. This nucleus, produced as a projectile-like fragment from the interaction of a 60 MeV/n40Ar beam with a Be target, has been separated by the LISE spectrometer. Several gamma rays from22O decay have been observed, from which a half-life of (2.25±0.15)s has been determined. Accurate excitation energies have been deduced for several states in22F. A partial beta decay scheme of22O has been established. Experimental results have been compared with shell model calculations. 相似文献
66.
67.
G. Pichard R. Chaminade J. Errera und P. Fleury 《Fresenius' Journal of Analytical Chemistry》1933,91(5-6):229-231
Ohne Zusammenfassung 相似文献
68.
69.
A. Lublin M. W. Goldblatt N. O. Engfeldt H. Bierry L. Moquet P. Fleury J. J. Awad L. Lorber C. Gerhardt M. H. P. Sitsen E. Herzfeld M. Händel A. Goldfederova Schenk J. Snapper A. Grünbaum G. Ljunggren W. Stepp J. Rothmann-Mannheim O. v. Fürth D. Charnass G. Gorr und J. Wagner 《Fresenius' Journal of Analytical Chemistry》1928,73(1-3):115-127
Ohne Zusammenfassung 相似文献
70.
An efficient one-pot procedure for the synthesis of ionic liquids based on nitrogen-containing heterocycles, imidazolium or pyridinium under ‘green chemistry’ conditions has been described. Imidazolium salts and DBU have been found to catalyze efficiently the benzoin condensation giving good yields within very short reaction time using solvent-free microwave activation conditions. 相似文献