Definitive production of intact organic pentacation radical: Octafluoronaphthalene ionized in intense femtosecond laser fields

Abstract

We demonstrate the production of long-lived octafluoronaphthalene pentacation radical in gas phase by tunneling ionization using 1.4 μm femtosecond laser pulses. Multiply charged molecular cations are definitively identified by their m/z, isotopic structure, and peak shape using time-of-flight mass spectrometry. The tetracation yield relative to the trication radical yield is 0.33 that is the highest value obtained to date. The yield of pentacation radical relative to tetracation is 0.025. Our results show that the use of perfluoro-aromatics is the promising way to approach intact highly charge states.