Molecular photoelectron spectroscopy. Part VI. Water, methanol, methane, and ethane

Abstract

The helium 584 Å photoelectron spectra of water, methanol, methane, and ethane have been obtained using retarding grid velocity analysis, and their main features are discussed in relation to possible molecular orbital structures, making use of differences in bonding character deduced from the shapes of the band envelopes. In only one case (H₂O, first ionisation potential) was vibrational structure detected. A revised configuration for methanol is proposed from comparisons with methane and water. Comparison between methane and ethane indicates that the highest energy levels in ethane involve antisymmetric (C–H bonding) orbitals rather than symmetric (C–C bonding).