Microhydrated fluorobenzene cation clusters, C6H5F+-(H2O)n with n = 1 and 2, were characterized by IR photodissociation spectra in the O-H stretch range and UB3LYP/6-31G* calculations. The intermolecular C6H5F+-H2O potential features several minima with charge-dipole orientation and comparable binding energies (D-0 similar to 9 +/- 1 kcal/mol). The C6H5F+-H2O spectrum is consistent with a structure in which the O atom of H2O approaches the C6H5F+ cation from above the aromatic plane. The C6H5F+-(H2O)(2) spectrum reveals the presence of two isomers, in which either a (H2O)(2) dimer or two single H2O ligands are attached to C6H5F+. The detected C6H5F+-(H2O)(1,2) complexes were unreactive with respect to nucleophilic substitution. (c) 2005 Elsevier B.V. All rights reserved.