The various dissociation thresholds of phenol(+)center dot center dot center dot Ar-3 complexes for the consecutive loss of all three Ar ligands were measured in a molecular beam using resonant photoionization efficiency and mass analyzed threshold ionization spectroscopy via excitation of the first excited singlet state (S-1). The adiabatic ionization energy is derived as 68077 +/- 15 cm(-1). The analysis of the dissociation thresholds demonstrate that all three Ar ligands in the neutral phenol center dot center dot center dot Ar-3 tetramer are attached to the aromatic ring via pi-bonding, denoted phenol center dot center dot center dot Ar-3(3 pi). The value of the dissociation threshold for the loss of one Ar ligand from phenol(+)center dot center dot center dot Ar-3(3 pi), similar to 190 cm(-1), is significantly lower than the binding energy measured for the pi-bonded Ar ligand in the phenol(+)center dot center dot center dot Ar(pi) dimer, D-0 = 535 +/- 3 cm(-1). This difference is rationalized by an ionization-induced pi -> H isomerization process occurring prior to dissociation, that is, one Ar atom in phenol+center dot center dot center dot Ar-3(3 pi) moves to the OH binding site, leading to a structure with one H-bonded and 2 pi-bonded ligands, denoted phenol(+)center dot center dot center dot Ar-3(H/2 pi). The dissociation thresholds for the loss of two and three Ar atoms are also reported as 860 and 1730 cm(-1). From these values, the binding energy of the H-bound Ar atom can be estimated as 870 cm(-1).