The phosphorescence spectra in toluene glass, recorded with a delay of 150 ms after excitation and a gate of 50 ms, are also shown in Figure . The structured phosphorescence spectra of the three compounds all align, with a lPL of 2.62 eV (473 nm) at the peak. Since the origin of the phosphorescence comes neither from donor nor acceptor, it must originate from a new state. Based on the structured shape of the phosphorescence spectra as well as the insight gained from quantum chemical calculations (vide infra),