Substituenteneinfluss bei der massenspektrometrischen Fragmentierung: Untersuchungen an N-methyl-β,β′-diphenyl-diäthylaminen. 19. Mitteilung über das massenspektrometrische Verhalten von Stickstoffverbindungen

Some different substituted N-methyl-β,β′-diphenyl-diethylamines (I) were investigated mass spectrometrically. The main fragmentations and their genesis are summarized in Scheme 2. The molecular ion generates the major fragmentions a (m/e 148) and b (m/e (147 + X)); c (m/e 105) is formed from a and d (m/e (104+X)) from b by further decomposition. The logarithms of the ratios of the relative ion intensities a/b , c/a and d/b were correlated according to the Hammett equation with different substituent constants. The following correlation coefficients (at 20ev) were found: r = 0,98 (σ⁺), r = 0,63 (σ) and r = 0,96 (σ) respectively. On the basis of the above Hammett correlations, the value of this kind of investigation for the elucidation of mass spectral fragmentation mechanisms is discussed.