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

The trans-1-naphthol/H2O 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 S1 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.