Photoelectron spectra and bonding in phosphorus compounds
Abstract
The microwave spectrum, dipole moment and low frequency vibrational states for phosphabenzene
Abstract The microwave spectrum of the ground vibrational state and seven lowfrequency vibrational states for phosphabenzene (C5H5P) have been assigned. The small positive inertial defect and the alternation of intensities due to nuclear spin statistics for the ground state confirm a plannar structure with C2v symmetry. A PC bond distance of 1.70–1.73 A and 〈CPC of 101°–104° were estimated based on plausible assumptions for the other ring parameters. Four low-frequency fundamental modes of vibration were identified and vibrational assignments discussed. The nuclear spin statistics indicate that three of these modes were antisymmetric to the C2 axis while one mode was symmetric. The dipole moment has been determined as 1.54±0.02 D.
A modification of INDO for interpretation of photoelectron spectra
Abstract It is possible to attain improved agreement between photoelectron-spectroscopic ionzation potentials and theoretical orbital energies simultaneously for all electrons of some hydrocarbons by a suitable parametrization of INDO in its modified form, MINDO. The changed parameters concern mainly the resonance integrals Hμν for which the separate cases of interaction are treated separately. The new procedure gives orbital energies in acceptable agreement with the photoelectron spectra of benzene, methane, ethane, and ethylene. As the procedure might be useful for photoelectron-spectroscopic studies of hydrocarbons it will be referred to as SPINDO (Spectroscopic-Potentials-adjusted-INDO).