The threshold photoelectron photoion coincidence spectra of the rare gas dimers Ar-2, Kr-2, and Xe-2 have been measured in the photon energy region between the first and second dissociation limits of the dimer ions. It has been found that the C-2 (2)Pi(1/2u) states of Kr-2(+) and Xe-2(+) completely dissociate via an optical transition to the repulsive B-2 (2)Pi(1/2g) state, while that of Ar-2(+) does not dissociate.