Fragmentation studies of tetrahydropyridocarbazole derivatives by EI, ESI‐MS/MS and FAB

Article type: Research Article

Authors: Romeiro, Gilberto A.^; | Ferreira, Vitor F. | Costa, Marília dos S. | Joaquim, Alexandre M. | Carneiro, José Walkimar de M. | Kammerer, Bernd

Affiliations: Instituto de Química – GQO/GQI/CEG, Universidade Federal Fluminense, Campus do Valonguinho S/N, Niteröi, CEP 24210‐150, RJ, Brazil | Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, D‐72076 Tübingen, Germany

Note: [] Corresponding author.

Abstract: Four tetrahydropyridocarbazole derivatives were analysed by different mass spectrometry techniques: electrospray ionization, fast atom bombardment and by low and high resolution 70 eV electron ionization. Retro Diels Alder is the main fragmentation pathway, whereas other pathways leading to [M−1]+, [M−CH3]+ and double charge ions also occur to considerable extents. Semi‐empirical calculation provided some evidence on the nature of tropylium ions [M−1]+. Calculation of ΔHf0 indicated that [M+−1] could be formed preferentially when a hydrogen atom is lost from the methyl substituent of the homoaromatic ring.

Journal: Spectroscopy, vol. 15, no. 1, pp. 19-25, 2001