Photoelektronenspektroskopische Untersuchungen an Bor-Verbindungen, IV1 / Ionisierungsenergien und Geometrie von Tetrazadiborinen Photoelectronspectroscopic Investigations on Boron Compounds, IV1 Ionization Energies and Geometry of Tetrazadiborines

The photoelectron (PE) spectra of five boron-substituted derivatives of tetrazadiborine are presented. They are discussed on the basis of a structural model (twist form of the ring system) which results from simple extended HÜCKEL calculations. Orbital energies calculated by the CNDO/S method agree quite well with observed ionization energies. According to these at least the first three bands correspond to ionizations from π-orbitals. Evidence for strong π-interactions can be deduced by comparison with PE spectra of diaminoboranes.