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1.
Zusammenfassung Der Einfluß verschiedener Substituenten auf das Fragmentierungsverhalten von Arylalkylphosphonaten wird diskutiert. Während einige der beobachteten Zerfallsreaktionen analog zu den bei Carbonsäureestern gefundenen verlaufen (z. B.McLafferty-Umlagerung, doppelte Wasserstoffumlagerung bei Estern mit höheren Alkoholen), treten zusätzliche Umlagerungen auf, die für Ester der phosphorigen und der Phosphorsäure typisch zu sein scheinen (z. B. Eliminierung der Phosphor- und Sauerstoffatome unter Rekombination von Kohlenstoffresten).
The influence of various substituents on the fragmentation behavior of aryl alkyl phosphonates is discussed. Several fragmentation reactions occur as observed with carbonic acid esters (e. g.,McLafferty rearrangement and double hydrogen transfer with esters of higher alcohols). In addition, rearrangements may take place which seem to be typical for esters of the phosphorous and phosphoric acid (e. g., expulsion of the phosphorus and oxygen atoms accompanied by recombination of carbon residues). *** DIRECT SUPPORT *** A3615112 00008
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2.
Zusammenfassung Durch Untersuchung einer Reihe von Steroidlactonen konnte gezeigt werden, daß in einem komplexen Kohlenwasserstoffgerüst die von der Lactongruppierung ausgelöste Fragmentierung gegenüber anderen Prozessen von sekundärer Bedeutung ist, ausgenommen wenn sie zu besonders stabilen Spaltprodukten führt, oder wenn strukturelle Faktoren, wie z. B. Ringspannung, von der Lactongruppierung eingeleitete Bruchstückbildung begünstigen. In solchen Fällen können massenspektroskopische Untersuchungen mit Erfolg auf Strukturprobleme angewandt werden.Mit 6 Abbildungen.Herrn Prof. Dr.F. Wessely in Verehrung zum70. Geburtstag.  相似文献   

3.
The fragmentation behaviour of diarylamines in a mass spectrometer can be interpreted most plausib by assuming carbazole cyclization reactions. As a first step the loss of a hydrogen atom is presumed, followed by another hydrogen loss resulting in the formation of the carbazale structure. Investigations of 10 diarylamines show that the probability of cyclization depends on the size of the π-electron system.  相似文献   

4.
Mass spectra of compounds of the kawain-type show significant ions, which are formed by unexpected hydrogen transfers. The spectra of deuterated kawains give information about the origin of the hydrogen atoms involved.  相似文献   

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6.
The fragmentation behavior of derivatives of benzisothiazole-S-dioxide is discussed. A series of degradation processes typical for this class of compounds is observed whose relative importance, however, largely depends upon substituents present. Provided it is energetically favorable fragmentation of the substituents (frequently followed by expulsion of SO2) prevails, otherwise degradation of the heteroaromatic ring is observed (sometimes with rearrangements involving the SO2 group). No parallels between thermal and electron-impact induced rearrangements have been observed.  相似文献   

7.
The mass spectrometric fragmentation behaviour of pheophorbides is discussed.  相似文献   

8.
A possibility has been found to carry out corrections on the mass spectrometric determination of the hydrocarbon groups in non-olefinic petrols on the basis of the measurements of a single test mixture with sufficient accuracy. A simple method is described for the elimination of the systematic errors in petrol analyses carried out with other instruments than those employed for the calibration factors. The results have also confirmed the conclusions of Benz that with such a method in different laboratories no extensive calibrations are required.  相似文献   

9.
The possibilities and limitations for localization of substituents in porphyrins from the fragmentation patterns of porphyrinogens are discussed.  相似文献   

10.
The possibility of elimination reactions without participation of the positive charge and/or electron deficient centers, in particular the loss of RCOOH, was investigated for molecular and fragment ions. Such processes, which could be referred to as quasithermal or quasi-photochemical reactions, were found to be absent or insignificant.  相似文献   

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