Photodetachment photoelectron spectroscopy of mass selected anions: anthracene and the anthracene-H2O cluster

Photodetachment photoelectron spectroscopy is applied for investigation of mass selected and supersonic jet cooled anthracene and anthracene-water dimers. Electron affinities are directly measured to be 530±5 meV for anthracene and 770±5 meV for anthracene-water. This shift in electron affinity due to H2O attachment is small and explained by the delocalization of the surplus electron in anthracene. Whereas for the cluster no vibrational structure is observed, for anthracene a short progression in ν12 is resolved. The anthracene S0–T1 transition energy in the gas phase is 1.869 eV ± 5 meV.