Investigation of the Electronic and Vibrational Structures of the 2-Furanyloxy Radical Using Photoelectron Imaging and Photodetachment Spectroscopy via the Dipole-Bound State of the 2-Furanyloxide Anion.

Abstract

The 2-furanyloxy radical is an important chemical reaction intermediate in the combustion of biofuels and aromatic compounds. We report an investigation of its electronic and vibrational structures using photoelectron and photodetachment spectroscopy and resonant photoelectron imaging (PEI) of cryogenically cooled 2-furanyloxide anion. The electron affinity of 2-furanyloxy is measured to be 1.7573(8) eV. Two excited electronic states are observed at excitation energies of 2.14 and 2.82 eV above the ground state. Photodetachment spectroscopy reveals a dipole-bound state 0.0143 eV below the detachment threshold and 25 vibrational Feshbach resonances for the 2-furanyloxide anion. The combination of photodetachment spectroscopy and resonant PEI yields frequencies for 18 out of a total of 21 vibrational modes for the 2-furanyloxy radical, including all six of its bending modes. The rich electronic and vibrational information will be valuable for further understanding the role of 2-furanyloxy as a key reaction intermediate of combustion and atmospheric interests.