Photodissociation spectroscopy and dynamics of the CH₂CFO radical

Abstract

<jats:p>The photodissociation spectroscopy and dynamics resulting from excitation of the B̃ 2A″←X̃ 2A″ transition of CH2CFO have been examined using fast beam photofragment translational spectroscopy. The photofragment yield spectrum reveals vibrationally resolved structure between 29 870 and 38 800 cm−1, extending ∼6000 cm−1 higher in energy than previously reported in a laser-induced fluorescence excitation spectrum. At all photon energies investigated, only the CH2F+CO and HCCO+HF fragment channels are observed. Both product channels yield photofragment translational energy distributions that are characteristic of a decay mechanism with a barrier to dissociation. Using the barrier impulsive model, it is shown that fragmentation to CH2F+CO products occurs on the ground state potential energy surface with the isomerization barrier between CH2CFO and CH2FCO governing the observed translational energy distributions.</jats:p>