Mass-spectrometric study of benzopyridosilaazepines and -azepinones

The influence of various structural factors on the dissociative ionization of benzopyridosilaazepines and -azepinones has been investigated. It has been shown that the mass spectra can be used to identify isomeric benzopyridosilaazepinones with respect to the position of the amide fragment in the central heterocycle. The anomalously high intensity of the ion [M-H]+ in the mass spectra of these compounds is attributed to fragmentation of the molecular ions from the open form. © 1986 Plenum Publishing Corporation.