title: Side-chain effects on the electronic relaxation of radicals followed by time-resolved pump-probe spectroscopy: 2,3-dimethylbut-2-yl vs tert-butyl.
abstract: The excited-state lifetime of the 2,3-dimethylbut-2-yl (DMB) radical, a hexyl isomer, upon electronic excitation into the 3p Rydberg state at 265 nm, is measured by femtosecond time-resolved photoionization. It is shown that the 3p state deactivates in a two-step process, which is well described by two time constants of 25 and 400 fs. The results are compared to tert-butyl (t-C(4)H(9)), another tertiary radical investigated before. Time-dependent DFT calculations confirm the earlier suggestion that curve crossings along the C-C coordinate play an important role in the excited-state deactivation.
authors.affiliation: Laboratoire Francis Perrin, CNRS URA 2453, CEA IRAMIS/Service des Photos, Atoms et Molécules, F-91191 Gif-sur-Yvette Cedex, France.
authors.forename: Bastian
authors.initials: B
authors.lastname: Noller
authors.forename: Lionel
authors.initials: L
authors.lastname: Poisson
authors.forename: Ingo
authors.initials: I
authors.lastname: Fischer
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Mestdagh