Photoelectron spectra of electron-rich olefins and an isostructural boron compound; olefins of exceptionally low first ionisation potential

Abstract

The photoelectron (P.E.) spectra of C₂(NMe₂)₄ and {C[N(Me)CH₂]₂}₂ each show five bands below 10·5 eV with the first vertical ionisation potential at 5·95 or 6·06 eV (cf., C₂H₄, 10·5 eV; Na 5·1 eV), as is consistent with their strong reducing properties; these bands are assigned as π levels of various symmetries on the basis of (i) a good fit for experimental data with a simple Hückel calculation, and (ii) comparison of the spectra of the isostructural molecules C₂(NMe₂)₄ and B₂(NMe₂)₄.