Mechanisms of the charge separation in the phosphorus tetramer dication P42+ Original Research Article

The charge separation reactions of P42+ have been investigated using the PEPIPICO (photoelectron-photoion-photoion coincidence) technique at photon energies between 25 and 48 eV. All four possible ion pairs are formed. The relatively low appearance energy of the ion pair P+ + PP3+ provides an estimate of ⩽ 25.4 eV for the vertical double ionization energy of P4. Dissociations producing P++P2+ or 2P+ are mainly sequential, proceeding via the intermediate ions PP32+ or PP22+ respectively.