Abstract: | The mass spectrometric behaviour of benzo-o]-1,4,7,10,13-pentaoxacycloheptadecane-14,17-dione (1), 3,6,9,12,15-pentaoxabicyclo15.3.1]heneicosa-1(21),17,19-triene-2,16-dione (2) and 1,15-dioxo-2,5,8,11,14-pentaoxa15](1,4)benzenophane (3) has been studied in detail with the aid of linked scans, mass-analysed ion kinetic energy spectra, collisionally activated decomposition experiments, exact mass measurements and different ionization techniques (electron impact, positive and negative ion chemical ionization, charge exchange, electron attachment). The very low abundance of molecular ions and the presence of abundant M + H]+ and M – H]+ ions under electron impact conditions indicate the presence of acidic and basic sites in the molecular ions and neutral molecules, respectively. |