CORE-IONIZATION ENERGIES AND THE ANOMALOUS BASICITY OF ARSABENZENE AND PHOSPHABENZENE

To help understand the anomalously low basicity of arsabenzene and phosphabenzene we have investigated the correlation between the core-ionization energies and proton affinities for arsabenzene, phosphabenzene, arsine, trimethylarsine, phosphine, and the methylphosphines. The results support the view that the low basicity is due to the inability of the aromatic compounds to undergo geometric rearrangement on protonation. Comparison of the Auger kinetic energies with core-ionization energies gives an estimate of 0.45 eV for the stabilization energy due to the resonance derealization of the charge on phosphine following core ionization. Further comparison of these quantities indicates that a methyl group and an aromatic ring are both electron donating compared to hydrogen. © 1979, American Chemical Society. All rights reserved.