Delayed ionization following resonant photon absorption and intracluster electron transfer

Abstract
Ionization of clusters comprised of paraxylene (PX) bound to NH3 and N(CH3)3 is studied following the absorption of photons through the perturbed S1 state of PX. In the case of PX ⋅ NH3 where the ionization potential of PX (8.445 eV) lies below that of NH3 (10.16 eV), ionization of the cluster near the ionization threshold of PX leads to the formation of the cluster ion (PX ⋅ NH3)+. By contrast, for clusters of PX ⋅ N(CH3)3 where the ionization potential of N(CH3)3 (7.82 eV) lies below that of PX, resonance absorption through high Rydberg states of PX below its I.P. leads to the production of N(CH3)+3 and H+⋅N(CH3)3, but no parent cluster ions. In this case, following photon absorption the ionization and formation of N(CH3)+3 is substantially delayed for times ranging from 160–200 ns, the longer values being obtained at lower photon energies.