Laser-evaporated chromium atoms are shown to insert into dioxygen to form CrO2 in solid argon. Annealing allows diffusion and reactions to form (eta(2)-O-2)(2)CrO2, which is characterized as [(O-2(-))(2)(CrO2)(2+)], a side-on bonded disuperoxo-chromium dioxide complex. The (eta(2)-O-2)(2)CrO2 complex further reacts with xenon atom doped in solid argon to give (eta'-OO)(eta(2)-O-2)CrO2(Xe), which can be regarded as an O-2 molecule weakly interacting with [(O-2)(2-) (CrO2)Xe2+], a side-on bonded peroxo-chromium dioxide-xenon complex. The results indicate surprisingly that xenon atom induces a disproportionation reaction from superoxo to peroxo and dioxygen complex.