Studies of femtosecond time-resolved photoelectron spectroscopy of Au3-(H2O)m clusters: Alteration of cluster relaxation dynamics of metal clusters by water molecules

► Relaxation dynamics of optically excited states of Au3- and Au3-(H2O)m were studied. ► One water molecule adsorbed on Au3- opened new photo-dissociation channels. ► More than one water molecules on Au3- inhibited photo-dissociation. ► Photochemistry is controlled by adjusting the number of adsorbed water molecules.