Photoinduced products from cold coronene clusters

Bréchignac, Ph.; Schmidt, M.; Masson, A.; Pino, T.; Parneix, P.; Bréchignac, C.

doi:10.1051/0004-6361:20053000

Cited by 56 publications

(62 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the spatially resolved observations of the CH band regions in few objects, mainly those that may give rise to the class B and C carriers of the AIBs (Goto et al 2003(Goto et al , 2007, have clearly triggered some new thought. More and more, an interplay between aliphatic and aromatic component is outlined, and the main astrophysical linking ingredient is supposedly the harsh UV irradiation (Goto et al 2003;Bréchignac et al 2005;Goto et al 2007;Sloan et al 2007;Pino et al 2008;Acke et al 2010). …”

Section: Evolutionary Scenarios Based On the 62 And 77 μM Aib Positmentioning

confidence: 99%

Nanostructuration of carbonaceous dust as seen through the positions of the 6.2 and 7.7μm AIBs

Carpentier

Féraud

Dartois

et al. 2012

A&A

Self Cite

View full text Add to dashboard Cite

Section: Evolutionary Scenarios Based On the 62 And 77 μM Aib Positmentioning

confidence: 99%

Nanostructuration of carbonaceous dust as seen through the positions of the 6.2 and 7.7μm AIBs

Carpentier

Féraud

Dartois

et al. 2012

A&A

Self Cite

View full text Add to dashboard Cite

“…To assess the plausibility of this formation process, we should compare it with dissociation mechanisms, which are dominated by photo-evaporation. Laboratory experiments on the photophysics studies of PAH clusters have shown that multiphoton excitation of coronene clusters produced in a gas aggregation source leads to the ejection of van der Waals bonded units (Bréchignac et al 2005;Schmidt et al 2006). The loss of a monomer in the cluster, characterized by a ∼0.76 eV binding energy (Podeszwa 2010), is much more likely to happen upon absorption of a low-energy photon than the breaking of chemical bonds, which require more than 4.8 eV of energy (Pino et al 2007).…”

Section: Implications For Haze Formation In the Stratosphere Of Jupitermentioning

confidence: 99%

Insights into the role of polycyclic aromatic hydrocarbon condensation in haze formation in Jupiter’s atmosphere

Biennier

Sabbah

Chandrasekaran

et al. 2011

A&A

View full text Add to dashboard Cite

Context. The haze in the atmosphere of Jupiter has been proposed to originate mostly from the condensation of low mass PAHs. Under this hypothesis, the transition of gas phase molecular species to solid particles is achieved by the formation of a critical nucleus composed of two small PAH molecules held together by van der Waals forces. Aims. Laboratory experiments coupled with theoretical calculations explore the thermodynamics and kinetics of PAH dimerization with the objective to assess this pathway in the production of nuclei of haze particles. Methods. We have performed experiments to identify the temperature range over which small PAH clusters form in supersaturated uniform supersonic flows. The kinetics of this formation has also been investigated. The chemical species present in the reactor are probed by a time-of-flight mass spectrometer equipped with a VUV laser for photoionisation of the neutral reagents and products. The experimental data were combined with theoretical calculations that employ careful consideration of the intermolecular interaction energies and intermolecular dynamics to estimate the binding energy, equilibrium constant, and rate constant. Results. We found that low-mass PAHs such as anthracene (C 14 H 10 ) and pyrene (C 16 H 10 ) can not homogeneously nucleate in the upper stratosphere at the altitude at which haze formation has been proposed to commence. Other chemical or physical processes should be considered to account for aerosol nuclei formation.

show abstract

“…PAH cations have received close attention with respect to their candidacy as DIB carriers (Alata et al 2010;Bréchignac & Pino 1999;Vanderzwet & Allamandola 1985;Leger & D'hendecourt 1985;Allamandola et al 1985). Salama, Allamandola, and co-workers have systematically examined the spectra of matrix isolated PAH radical cations, generating by in situ VUV photoionization of the isolated PAHs (Salama et al 1996).…”

Section: Introductionmentioning

confidence: 99%

“…Salama, Allamandola, and co-workers have systematically examined the spectra of matrix isolated PAH radical cations, generating by in situ VUV photoionization of the isolated PAHs (Salama et al 1996). Subsequently, Pino and co-workers used resonant two-photon ionization to prepare Ar tagged clusters of PAH cation radicals, which were then photodissociated to yield action spectra that are expected to closely resemble the absorption spectrum of the bare gas-phase cation (Bréchignac & Pino 1999). In the case of the phenanthrene cation radical, the derived oscillator strengh of the D 0 → D 1 transition (0.15) was some three orders of magnitude larger than inferred from the matrix spectrum.…”

Section: Introductionmentioning

confidence: 99%

On the electronic spectroscopy of closed-shell cations derived from resonance-stabilized radicals: Insights from theory and Franck-Condon analysis

Troy

Kable

Schmidt

et al. 2012

A&A

View full text Add to dashboard Cite

Context. Recent attention has been directed on closed-shell aromatic cations as potential carriers of the diffuse interstellar bands. The spectra of mass-selected, matrix-isolated benzylium, and tropylium cations were recently reported. The visible spectrum of benzylium exhibits a large Franck-Condon (FC) envelope, inconsistent with diffuse interstellar band carriers. Aims. We perform a computational analysis of the experimentally studied benzylium spectrum before extending the methods to a range of larger, closed-shell aromatic cations to determine the potential for this class of systems as diffuse interstellar band carriers. Methods. Density functional theory (DFT), time-dependant ((TD)DFT), and multi-configurational self-consistent field second-order perturbation theory (MRPT2) methods in concert with multidimensional FC analysis is used to model the benzylium spectrum. These methods are extended to larger closed-shell aromatic hydrocarbon cations derived from resonance-stabilized radicals, which are predicted to show strong S 0 → S n transitions in the visible region. The ionization energies of a range of these systems are also calculated by DFT. Results. The simulated benzylium spectrum was found to yield excellent agreement with the experimental spectrum showing an extended progression in a low frequency (510 cm −1 ) ring distortion mode. The FC progression was found to be significantly quenched in the larger species: 1-indanylium, 1-naphthylmethylium, and fluorenium. Excitation and ionization energies of the closed-shell cations were found to be consistent with diffuse interstellar band carriers, with the former lying in the visible range and the latter straddling the Lyman limit in the 13−14 eV range. Conclusions. Large closed-shell polycyclic aromatic hydrocarbon cations remain viable candidate carriers of the diffuse interstellar bands.

show abstract

Photoinduced products from cold coronene clusters

Cited by 56 publications

References 59 publications

Nanostructuration of carbonaceous dust as seen through the positions of the 6.2 and 7.7μm AIBs

Nanostructuration of carbonaceous dust as seen through the positions of the 6.2 and 7.7μm AIBs

Insights into the role of polycyclic aromatic hydrocarbon condensation in haze formation in Jupiter’s atmosphere

On the electronic spectroscopy of closed-shell cations derived from resonance-stabilized radicals: Insights from theory and Franck-Condon analysis

Contact Info

Product

Resources

About