Gas-phase Electronic Spectra of Coronene and Corannulene Cations

Abstract

Gas-phase electronic spectra of the coronene ( + C H 24 12 ) and corannulene ( + C H 20 10 ) cations complexed with helium have been recorded in a quadrupole ion trap at 5 K by photodissociation. The electronic spectrum of + C H 20 10 with two helium atoms was also measured to estimate the perturbation. This method is sufficient for an astronomical comparison because the shift due to the weakly bound helium is on the order of 0.2 Å.

Storage time dependent photodissociation action spectroscopy of polycyclic aromatic hydrocarbon cations in the cryogenic electrostatic storage ring DESIREE

“…While the reader is again cautioned against over-interpreting Fig. 6) is qualitatively sharper, 12 although the band maximum at 457 nm is the same within the uncertainty of the MPD measurements.…”

“…The rst, by Joblin and co-workers, recorded multi-photon photodissociation (MPD) action spectra of coronene ions inside a cryogenically cooled (35 K) Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer. 11 More recently, Maier and coworkers reported the photodissociation action spectrum of C 12 H 24 + -He complexes at approximately 10 K. 12 In the present experiments, which also employ MPD, isolated PAH ions relax at their intrinsic rates via infrared (IR) radiative cooling in the cryogenic ($13 K), collision free environment of the Double ElectroStatic Ion Ring ExpEriment (DESIREE). 13 The purpose of this contribution is to compare the results of these three very different implementations of cold ion action spectroscopy.…”

Fullerenes in Space

“…[37] However,s uch as cheme was not successful for coronene cation C 24 H 12 + itself. [38] In the case of C 60 + fragmentation occurs via the loss of C 2 units and in order to achieve arate of afew ions per millisecond the C 60 + internal energy needs to be significantly in excess of the threshold, in the range 20-30 eV, [39] dictating the use of an Xray laser.…”

Fullerene im Weltraum

“…Danach wurde durch Einstrahlung von 266 nm das Wasserstoffatom entfernt und die Entstehung des C 24 H 12 + ‐Ions beobachtet . Diese Vorgehensweise führte beim eigentlichen Coronen‐Kation C 24 H 12 + jedoch nicht zum Erfolg . Bei C 60 + verläuft die Fragmentierung über den Verlust von C 2 ‐Einheiten, sodass man die interne Energie von C 60 + weit über die Schwelle bis zu einem Bereich von 20–30 eV anheben muss, um eine Fragmentierung von wenigen Ionen pro Millisekunde zu erreichen .…”