AM1 and ESI/MS study of the Fragmentation of 4-Acyl Isochroman-1,3-Diones: Correlation between Electronic charges of Atoms and Fragmentations processes

摘要

Recently, it has been found a good correlation between the fragmentation processes of coumarins in electronic impact mass spectrometry (eims) and the electronic charges of the atoms of their hydrocarbon skeleton. The same results have been obtained with eims spectra of 4-acyl isochroman-1,3-diones and the electronic charges of their atoms. In this paper, the analytic method has been applied to ESI/MS mass spectra of a series of 4-acyl ischroman-1,3-diones to verify its reliability and extensibility. The results, which have been described for the very first time, show that fragmentations take place at the level of atoms bearing high positive charge, according to the nature of ionisation projectile. The results are in good agreement with the earliest studies.