Energy-dependent gas-phase fragmentation of fluorofullerene multiply charged anions (MCAs)

Abstract

Long-lived di- and trianions have been formed from fluorofullerenes in the gas phase by electrospray ionization. Fragmentation of multiply charged anions has been induced by multiple low-energy collisions. Two complementary dissociation experiments have been conducted. Firstly, unequivocal connectivity has been established between the precursor ion and the first and second generation of its product ions. Secondly, dianions have been studied in energy-resolved collisions, allowing the elucidation of the energetic demands of the dissociations. It was possible to study dianions with odd and even F numbers, possessing even and odd electron configurations, respectively. The fragmentation behavior is governed by the electronic stability of the anionic protagonists, in that ions with the less stable odd-electron configuration dissociate into species with the more stable even-electron configuration. Dianions with an odd electron count release an F˙ atom to turn into an even electron system while retaining the charge state. Dianions with an even electron count undergo a more energy demanding charge separation reaction (Coulomb explosion) into an F(-) anion and an even electron monoanion. The studied trianions behave accordingly. F2 loss is prominent only with monoanions within an even-to-even electron fragmentation cascade. The trianions are long-lived with lifetimes of at least 0.1 s.

Gas‐Phase Transformation of Fluorinated Benzoporphyrins to Porphyrin‐Embedded Conical Nanocarbons

“…Energy‐dependent CID experiments not only provide additional information on the different energy demands of the transformations, but also quantification of the individual yields of the cyclizations and the side reactions. Thus, the so‐called survival yields (SY) were plotted as a function of the collision energy in the center‐of‐mass frame ( E COM ), which is generated from the measured laboratory frame collision energy ( E lab ) and the masses of the collision gas and the precursor ion according to Equation …”

“…Thus, the so-called survival yields (SY) were plotted asafunctiono ft he collision energy in the center-of-mass frame (E COM ), which is generated from the measured laboratory frame collisione nergy (E lab )a nd the masses of the collision gas and the precursor ionaccording to Equation (1). [34]…”

Stability of Odd‐ Versus Even‐Electron Gas‐Phase (Quasi)Molecular Ions Derived from Pyridine‐Substituted N‐Heterotriangulenes

“…The prerequisites for efficient oxidation include aprotic solvents, low flow rates and analyte molecules with oxidation potentials below 1 V . Our previous research confirms the validity of these parameters . In the present case, the half‐wave oxidation potentials of all four compounds are low, ranging from 0.36 V for NTG to 0.56 V for NTGPy 3 as measured by cyclic voltammetry (all potentials are referenced against the ferrocene/ferrocenium (Fc/Fc + ) redox pair), and leading to the successful formation of their radical cations.…”

Influence of electronic and molecular structure on the fragmentation dynamic of even-electron carbocationic triangulenes and helicenes in the gas phase

“…Generally, the ion transfer settings vary due to spectra tuning. We have recently published several illustrative examples of the complementary application of QqToF and ion trap instruments …”