Triplet selectivity in surface ejection of electrons by laser-excited metastables of aniline

We utilize the phenomenon of surface electron ejection, induced by metastables, to measure the triplet-state lifetimes of aniline in molecular beams. The triplet population originates from optically excited S₁ vibronic states via intersystem crossing. The good correspondence of the measured lifetimes to previously reported values supports our notion that only excess electronic energy induces the electron ejection. Vibrationally excited ground state molecules with the same energy content do not induce the process.