Multiphoton ionization and zero kinetic energy photoelectron spectroscopy of the 1-naphthol(H2O) cluster

The trans -1-naphthol/H 2 O cluster was investigated by [1 + 1] resonantly enhanced multiphoton ionization and by [1+1 ′ ] zero kinetic energy photoelectron (ZEKE-) spectroscopy. In the electronically excited state of the cluster a bending vibration of 57 cm −1 appears with considerable intensity and is also present in combination with several intramolecular bands. Some other intermolecular vibrations in the electronically excited S 1 state are tentatively assigned. The ZEKE-spectrum reveals a progression in the intermolecular stretch with a harmonic frequency of 190.5 cm −1 . An ionization energy of 59133 cm −1 was determined from the ZEKE-spectrum.