STRUCTURAL CHARACTERIZATION OF ISOMERIC TRIAZOLOCOUMARINS BY HIGH-ENERGY AND LOW-ENERGY COLLISION SPECTROMETRY OF M+., [M+H]+ AND [M-H]- SPECIES

Two monomethyl- and four dimethyl-triazolocoumarin isomers were characterized by their electron impact mass spectra and by low-energy collision experiments performed on molecular ions M+. and other fragment ions with an ion-trap mass spectrometer. High-energy collision-activated dissociation measurements were performed on the protonated [M + H]+ and deprotonated [M - H]- molecular ion obtained by fast atom bombardment and M+. species produced by electron impact ionization on a double-focusing, reverse-geometry instrument. The data obtained allowed unequivocal structural identification of all the compounds investigated.