Ion-molecule complexes of the form Si+(C6H6)(n) and Si+(C6H6),Ar are produced by laser vaporization in a pulsed nozzle cluster source. These clusters are mass-selected and studied with ultraviolet (355 nm) photodissociation and resonance-enhanced infrared photodissociation spectroscopy in the C-H stretch region of benzene. In the UV, Si+(C6H6)(n) clusters (n = 1-5) fragment to produce the Si+(C6H6) mono-ligand species, suggesting that this ion has enhanced relative stability. IR photodissociation Of Si+(C6H6), complexes occurs by the elimination of benzene, while Si+(C6H6)(n) Ar complexes lose Ar. Resonances reveal C-H vibrational bands in the 2900-3300 cm(-1) region characteristic of the benzene ligand with shifts caused by the silicon cation bonding. The IR spectra confirm that the major component of the Si+(C6H6) ions studied have the pi-complex structure rather than the isomeric insertion products suggested previously.