Photoelektronenspektren von Verbindungen der V. Hauptgruppe, ΙII Methylhalogenverbindungen MeEHaI2 und Me2EHal / Photoelectron Spectra of Group V Compounds, III Methylhalogen Compounds MeEHal2 and Me2EHal

Abstract

The He I photoelectron spectra of certain MeEHal2 and Me2EHal compounds (E = (N), P, As, Sb; Hal = (F), Cl, Br, J; Me = CH3) are interpreted in terms of a “composite molecule” approach derived for C3vCs systems. Although an “internal standard” is missing here, substituent group-orbitals (nHal, C—H) may be classified with respect to their orientations in space (R, V, T). Ionisation energies are assigned according to this assumption. PE data of the isoelectronic EMe3/EHal3 compounds and of related molecules (Me2EH, MePH2, CF3PBr2) as well as EHMO calculations with partial inclusion of spin orbit coupling are used to confirm the assignments given for Me2EHal/MeEHal2 series. Correlations between PE ionisation energies (e.g. nE (IE)) and molecular or atomic properties are critically revised and discussed.