Photophysics of the galvinoxyl free radical revisited

Article Article scientifique Article Photophysics of the galvinoxyl free radical revisited eng 2012 author Grilj Jakob 641051 author Zonca Cédric 583747 author Lawson Daku Latevi Max 530149 author Vauthey Eric 0000-0002-9580-9683 133895 6352-6358 10.1039/c2cp23577c 1463-9076 http://xlink.rsc.org/?DOI=c2cp23577c The photophysical properties of the free neutral radical galvinoxyl were studied by a combination of femtosecond time-resolved spectroscopy and quantum chemical calculations. The electronic absorption spectrum is dominated by an intense band at 430 nm that is ascribed to the D9,10←D0 transitions. Upon photoexcitation at 400 nm, the population of the D9,10 states decays within less than 200 fs to the electronic ground state. This ultrafast internal conversion does not involve intramolecular modes with large amplitude motion as the measured dynamics does not show any significant dependence on the environment, but is most probably facilitated by a high density of electronic states of different character. Depending on the solvent, a weak transient band due to the galvinoxylate anion is also observed. This closed-shell species, which is fluorescent although its deactivation is also dominated by non-radiative decay, is generated upon biphotonic ionization of the solvent and electron capture. The ultrashort excited-state lifetime of the galvinoxyl radical precludes photoinduced disproportionation previously claimed to be at the origin of the formation of both anion and cation. Dewey 540 38 Département de chimie physique 142 false 687 Groupe Hauser 686 Groupe Vauthey PCCP. Physical chemistry chemical physics 14 18 1f420562-f2f7-464e-ab92-4f4053032d34 Article (Published version) Public ref01276.pdf 1826821 application/pdf openAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie physique

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Photophysics of the galvinoxyl free radical revisited	PCCP. Physical chemistry chemical physics			2012	909	691

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