The electronic states of 2-furanmethanol (furfuryl alcohol) studied by photon absorption and electron impact spectroscopies

The photoelectron spectrum of 2-furanmethanol (furfuryl alcohol) has been measured for ionization energies between 8 and 11.2 eV and the first three ionization bands assigned to $π3,$ $π2,$ and $no$ ionizations in order of increasing binding energy. The photoabsorption spectrum has been recorded in the gas phase using both a synchrotron radiation source (5–9.91 eV, 248–125 nm) and electron energy-loss spectroscopy under electric-dipole conditions (5–10.9 eV, 248–90 nm). The (UV) absorption spectrum has also been recorded in solution (4.2–6.36 eV, 292–195 nm). The electronic excitation spectrum appears to be dominated by transitions between π and π^* orbitals in the aromatic ring, leading to the conclusion that the frontier molecular orbitals of furan are affected only slightly on replacement of a H atom by the $–CH2OH$ group. Additional experiments investigating electron impact at near-threshold energies have revealed two low-lying triplet states and at least one electron/molecule shape resonance. Dissociative electron attachment also shows to be widespread in furfuryl alcohol.