Photofragmentation of mass-selected C+16 to C+36 clusters is investigated at two laser wavelengths: 532 and 355 nm. The depletion dependence on laser fluence leads to the number of absorbed photons, together with the photoabsorption cross section. From the knowledge of the internal energy deposited in the clusters before the fragmentation step, the dissociation energies are deduced. Clusters C+16 to C+29 are found to be less and less stable, whereas above C+30 an increased stability is observed.
The photodissociation dynamics of size-selected C + n clusters with 19 n 29 is analysed using visible and UV irradiation. Both the number of absorbed photons leading to dissociation, and the time decay of the associated internal energy state are determined. The measured dissociation time constants indicate an evaporative behaviour, where energy redistribution over the modes of vibration occurs before dissociation.The RRKM theory is therefore used and shown to lead to low dissociation energies. At the low levels of internal energy reached in our photodissociation experiments, a more appropriate model is proposed, which accounts for a restricted redistribution of energy inside the cluster. This model leads to dissociation energies ranging from 4.05 to 3.3 eV.One-photon dissociation is also observed with photon energies close to 4.5 eV. On the one hand, this suggests a dissociative process for this photo-excitation wavelength. On the other hand, it allows to get upper limits for the dissociation energies.
Photodissociation of jet-cooled, mass-selected [Formula: see text] clusters with 16≤n≤36 has been analyzed as a function of the dissociation laser fluence. From the dependence of the [Formula: see text] depletion, the number of absorbed photons and the absorption cross section have been determined. The dissociation energy is deduced from the internal energy before fragmentation. A decreasing stability is observed from [Formula: see text] to [Formula: see text]. Above [Formula: see text], two isomeric forms are found, with one having a higher stability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.