Influence of electronic and molecular structure on the fragmentation dynamic of even-electron carbocationic triangulenes and helicenes in the gas phase.
Jakob Felix HitzenbergerAgnes UhlJürgen SchatzThomas DrewelloPublished in: Journal of mass spectrometry : JMS (2018)
Stable, long-lived organic cations are directly transferred by electrospray ionization (ESI) from solution into the gas phase where their collision-induced dissociations (CID) are studied by tandem mass spectrometry. Three related types of triphenyl carbenium ions are investigated, in which the meta positions are either substituted by methoxy groups or tertiary nitrogen bridges, including tetramethoxyphenylacridinium (TMPA+ ), dimethoxyquinacridinium (DMQA+ ), and triazatriangulenium (TATA+ ) cations. These ions are triangular in shape with increasing degrees of planarity. Fragmentation occurs at the periphery of the triangular molecule, involving the methoxy groups and the substituent of the nitrogen bridge. Each initial precursor cation is an even electron (EE) system and shows competing dissociations into both even (EE) and odd electron (OE) fragment ions. The latter reaction is a breach of the classic 'even-electron rule' in mass spectrometry. While the EE fragment dissociates similar to the precursor, the OE fragment ion shows a rich radical-induced fragmentation pattern. Two driving forces direct the fragmentation of the EE precursor ion toward OE fragment ions, including the release of stabilized radicals and the extension of the π-system by increasing planarization of the triangulene core. Copyright © 2017 John Wiley & Sons, Ltd.
Keyphrases
- tandem mass spectrometry
- liquid chromatography
- quantum dots
- mass spectrometry
- high performance liquid chromatography
- gas chromatography
- high glucose
- water soluble
- ionic liquid
- ultra high performance liquid chromatography
- aqueous solution
- solar cells
- diabetic rats
- electron transfer
- ms ms
- simultaneous determination
- high resolution
- drug induced
- solid phase extraction
- molecular docking
- endothelial cells
- molecular dynamics simulations
- capillary electrophoresis
- stress induced