Fast beam photofragment translational spectroscopy of the phenoxy radical at 225 nm, 290 nm, and 533 nm

Abstract

Photodissociation of the phenoxy radical (C₆H₅O) is investigated using fast beam photofragment translational spectroscopy. Phenoxy radicals are generated through photodetachment of phenoxide anions (C₆H₅O⁻) at 532 nm. Following photoexcitation of the radicals at 225 nm (5.51 eV), 290 nm (4.27 eV), or 533 nm (2.33 eV), photofragments are collected in coincidence to determine their masses, translational energy, and scattering angle for each dissociation event. Two-body dissociation yields exclusively CO + C₅H₅, and three-body dissociation to CO + C₂H₂ + C₃H₃ and CO + C₅H₄ + H is also seen at the two higher energies. The translational energy distributions for two-body dissociation suggest that dissociation occurs via internal conversion to the ground electronic state followed by statistical dissociation. The absorption of an additional 532 nm photon in the photodetachment region provides some C₆H₅O radicals with an additional 2.33 eV of energy, leading to much of the two-body dissociation observed at 533 nm and the three-body dissociation at the two higher excitation energies.