DECOMPOSITION CHANNELS ALTERNATIVE TO REMOTE-CHARGE FRAGMENTATIONS OBSERVED IN MASS-SPECTROMETRY OF ALKYLTRIMETHYLAMMONIUM CATIONS

A series of alkyltrimethylammonium cations, generated by fast atom bom bardment from 1-dodecanaminium-, 1-tetradecanaminium- and 1-hexadecana minium-N,N,N-trimethyl bromides, were studied by high-energy collision s and comparison with N,N,N-trimethyl-d(9) labelled analogues, The res ults show that, together with remote-charge fragmentation processes, a lkyltrimethylammonium cations exhibit further decomposition pathways w hich may be explained by interaction between the alkyl chain and the m ethyl group linked to the nitrogen atom, The sharp interruption of rem ote-charge fragmentation at the C-5 atom was observed for all compound s and explained as due to the formation of an energetically favoured s ix-membered cyclic structure.