Photoinitiated intracluster ion-molecule reactions of phenylsilane dimer cation have been investigated for the first time. The reaction products were the same as those reported in the gas-phase study. The photodepletion spectrum of the parent dimer ion and the action spectra of the reaction products were observed in the region of 6000-22 000 cm(-1). All the spectra exhibit an intense band appearing in near-IR region, which is associated with the charge resonance (CR) transition of the dimer ion. It was found that the intracluster reactions are preferential for an isomer of the dimer cation having a parallel conformation of two phenyl rings which exhibits the CR transition.