MASS-SPECTRAL FRAGMENTATION PATTERNS OF N,N'-ALKYLIDENE AND N,N'-ARYLIDENE BISAMIDES

The electron impact mass spectra of several gem-bisamides are studied, The dominant peaks in the spectra of alkylidene and arylidene bisalky lamides are formed by the cleavage of the C-N bond of the amido group with charge retention on the nitrogen atom, This fragmentation, follow ed by the loss of a neutral molecule, leads to characteristic immonium ions as the base peaks, In contrast, alkylidene and arylidene bisaryl amides undergo cleavage of the C-N bond with charge retention on the c arbon atom, leading to the benzoyl ion C6H5CO+ as the dominant peak. ( C) 1997 by John Wiley & Sons, Ltd.