Experimental observations following the ionization of neutral group 11 metal/argon complexes have revealed the presence of doubly charged ions of the form $[{\mathrm{M\cdot Ar}}_n{]}^{\text{2+}}$ for n in the range 1–6. Of particular interest are two features of the results. First, the unexpected stability of the dimer ions, $[\mathrm{M\cdot Ar}{]}^{\text{2+}},$ since similar species involving a molecule rather than a rare gas atom are often unstable with respect to charge transfer. Ab initio calculations show the dimers owe their stability to a combination of a strong electrostatic interaction and the high ionization energy of argon. A second feature to the results is the high relative intensities of the $[{\mathrm{M\cdot Ar}}_4{]}^{\text{2+}}$ and $[{\mathrm{M\cdot Ar}}_6{]}^{\text{2+}}$ ions. Calculations show these complexes to consist of square-planar $D_{\text{4h}}$ structures, with the additional two atoms in $[{\mathrm{M\cdot Ar}}_6{]}^{\text{2+}}$ occupying axial sites, which are Jahn–Teller distorted. The calculated relative binding energies support the preferential stability of these two structures.