The structures and vibrational spectra of the monomer and dimer of copper dichloride as well as the 1:1 complexes with aluminum and gallium trichloride, CuAlCl5 and CuGaCl5, have been studied using ab initio and density functional methods. For all molecules, equilibrium structures corresponding to minima on the potential energy surface were found to possess the ideal and expected D-infinity h, D-2h, or C-2v symmetries, respectively. These complexes are, however, easily distorted through bending of the terminal chlorines connected to copper in the plane of the singly occupied orbital in Cu d(9). Calculated bending potentials show that the corresponding modes are very soft. For the higher associates of CuCl2, vibrational bands that may facilitate the verification of the structures are presented.