C21H25Br2ClCuN2O6 is tetragonal, P43212; the unit-cell parameters at 120(2)K are a = 13.5447(3)Å, c = 13.6524(7)Å, Z =4, V = 2504.65(15)Å3 and Dx = 1.751 g cm–3. The final R value was R1 = 0.0259 for 2480 reflections with I > 2s(I). The complex cation is nearly planar and has a 2-fold symmetry and constructed from mixed-chelates of diamine and acetylacetonate. Two ClO4 – ions are bound weakly above and below of the chelate plane, so that the coordination environment around the copper ion is approximately octahedral. The five-membered ring containing nitrogen and carbon atoms is puckered.