Fast atom bombardment of some asymmetric compartmental [1+1] Schiff bases

New compartmental ligands (L), containing a N2O2 Or N3O2 Schiff base and an O2O4, O2O5 or O2O6 'crown like' coordination site, have been prepared by reaction of the appropriate diformyl- and polyamine precursors, The related amine derivatives have been obtained by reduction of the imine analogues with NaBH4. The mass spectrometric behaviour of these compounds has been studied by fast atom bombardment mass spectrometry, which mainly leads to the facile production of protonated [MH](+) and cationized [MNa](+) molecules, The mass analysed ion kinetic energy spectra of these ionic species show that the primary fragmentation patterns strongly depend on the crown dimensions and on the imine-amine structure of the nitrogen-containing chain, Macrocyclic rare earth complexes Me(L)(H2O)(4)(Cl)(3) (Me = Ce, Y), prepared by a template procedure, have been also studied under the same experimental conditions, proving that the presence of the metal ion leads to a strong reduction of the number of primary decomposition pathways.