Vibronic structure of the 3s Rydberg state of the 2-methylallyl radical

Exploring the Excited-State Dynamics of Hydrocarbon Radicals, Biradicals, and Carbenes Using Time-Resolved Photoelectron Spectroscopy and Field-Induced Surface Hopping Simulations

“…The states C and D have been assigned as two 3p Rydberg states lying in the molecular plane, which are dark or only weakly allowed in one-photon absorption 73,82,84 . The bright E ( 2 B1) state is centered around 5.5 eV 73,92,93 and has been identified as a 3p Rydberg state perpendicular to the allyl plane 73,84 . Several higherlying Rydberg states, close to the experimental IP of 8.14 eV 70 have also been reported 70 .…”

“…In addition, for 2MA, a weak absorption has been observed around 4.75 eV 72,92,96,97 , and has been assigned to a 3s Rydberg state, which is only weakly allowed in one-photon absorption 72,92 .…”

Excited‐State Dynamics of the 2‐Methylallyl Radical

“…An overtone of ν 17 , the 17 1 18 1 combination band or the ν 16 fundamental might contribute to this band. Ns‐work using pyrolysis for generation of 2‐MA reported a full width at half maximum (FWHM) of 35 cm −1 for some bands,9a while experiments that relied on radical generation by photolysis yielded radicals with lower internal temperatures 9b. In the one‐photon REMPI spectrum (not shown) several further bands can be identified by comparison with the ns‐spectrum.…”

“…Since individual vibronic bands were resolved and assigned in the MPI spectrum obtained with ns‐lasers,9b a ps‐laser system is particularly suitable to investigate the dynamics of these bands. In Figure 1 a [2+1′] the MPI spectrum of 2‐MA is depicted, obtained by tuning the output of a ps‐OPG (optical parametric generator over the excitation region.…”

“…In Figure 1 a [2+1′] the MPI spectrum of 2‐MA is depicted, obtained by tuning the output of a ps‐OPG (optical parametric generator over the excitation region. For ionization, one photon of the third harmonic of a ps‐Nd:YLF laser at 351 nm was sufficient, because the ionization energy was measured to be 7.877 eV 9b. As visible a number of bands can be resolved and in particular the B 0 0 origin band is clearly discernible.…”