Electron ionization of W(CO)6: Appearance energies

Abstract

The electron ionization (EI) of W(CO)6 has been studied in detail using a high resolution crossed electron-molecular beams technique. We have detected singly (W+, CW+, (CO)xW+ (x=1–6), (CO)yCW+ (y=1–3), CO+) and doubly charge positive ions (W2+, CW2+, (CO)xW2+ (x=1–6) and (CO)yCW2+ (y=1–3)). The relative partial cross sections for formation of particular ions have been measured and the breakdown curves constructed. The ionization energies (IE) for single (8.47±0.06eV) and double ionization (22.90±0.08eV) of the molecule, as well as the appearance energies (AEs) for the dissociative ionization channels for singly and doubly charged ions have been estimated from experimental ion efficiency curves. On the basis of the IEs and AEs values we have calculated sequential bond dissociation energies (BDEs) of different bonds in the positive ions formed from W(CO)6.