Intramolecular decay of some open-shell polyatomic cations

Abstract

Radiative and non-radiative relaxation processes of selected open-shell polyatomic cations in various vibrational levels of their lowest excited electronic states have been studied by two complementary techniques. Fluorescence quantum yields and lifetimes are obtained by photoelectron–photon coincidence measurements, and laser-excited fluorescence of rotationally cooled cations provides lifetime data at much higher resolution and for further levels. The information forthcoming on the intramolecular decay of isolated CO⁺₂B²Σ⁺_u, ClCN⁺B²Π, H–(—CC–)₂—H⁺òΠ_u and 1,2,4,5-tetrafluorobenzene⁺B²B_1u is discussed.