Long-lived negative ion formation by Alq3

Organic electroactive molecule Alq3 has been investigated by means of Electron Capture Negative Ion Mass Spectrometry (ECNI MS). Only extremely long-lived parent molecular NIs were detected in the electron energy region 0-1 eV. Mean lifetime [tau]a of these ions decreases from ~800 [mu]s at ~0 eV to 400 [mu]s at 0.8 eV. The results of [tau]a measurement allow to estimate adiabatic electron affinity 1<EAa<3 eV in the framework of the model of autodetachment elaborated by Christophorou and co-workers.