Contrasting behavior of tetracene and perylene in collision-induced dissociation: a theoretical interpretation

✍ Scribed by Fleurat-Lessard, Paul; Pointet, Karine; Milliet, Arielle

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 107 KB
• Volume: 34
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(199907)34:7<768::aid-jms833>3.0.co;2-3

✦ Synopsis

Dimethyl ether chemical ionization mass spectrometry of polycyclic aromatic hydrocarbons (PAHs) leads to [M Y 13] Y and [M Y 45] Y ions. The process leading to these ions is sensitive to the proton affinity of the PAH. Collision-induced dissociation observations on [M Y 45] Y ion also show that tetracene has a peculiar reactivity in comparison with perylene, despite the similar physico-chemical properties of these two molecules. Ab initio calculations were used to establish a potential energy profile for the mechanistic pathway of [M Y 13] Y and [M Y 45] Y formation. [M Y 45] Y ions result from the addition of CH 3 -O-CH 2 Y to PAHs. A 1,2-hydride transfer followed by a 1,4-proton transfer and a loss of methanol subsequently lead to the formation of [M Y 13] Y ions. For tetracene, the 1,2-hydride transfer does not occur, as it would lead to a thermodynamically unstable non-planar ion.