The title compound [Cu(dafone)2(DMF)2]?2ClO4 1 (dafone = 4,5-diazafluoren- 9-one, dmf = N,N?-dimethyl formamide) was synthesized by the reaction of Cu(ClO4 )2 and dafone in DMF solution at room temperature with pH = 3.0. The single-crystal X-ray analysis has revealed that 1 crystallizes in monoclinic, space group P21/n with a = 8.4853(8), b = 13.1520 (14), c = 14.3866(12) ?, β = 102.629(3)o, V = 1566.7(3) ?3, C28H26Cl2CuN6O12, Mr = 773.00, Z = 2, Dc = 1.639 g/cm3 , F(000) = 790, μ = 0.942 mm-1, the final R = 0.0438 and wR = 0.1214 for 3165 obser- ved reflections with I > 2σ(I). X-ray analysis shows that compound 1 has unsymmetric chelation of dafone with one Cu–N bond being much longer than the other. Coordination geometry of Cu is a highly distorted octahedron and the whole structure is stabilized by π-π stacking and static attractive forces from [ClO4]- anions. Based on the crystal data, quantum chemistry calculation at the DFT/ B3LPY level was used to reveal the electronic structure of 1. The title compound [Cu (dafone) 2 (DMF) 2]? 2ClO4 1 (dafone = 4,5-diazafluoren- 9-one, dmf = N, N? -dimethyl formamide was synthesized by the reaction of Cu (ClO4) 2 and dafone in DMF solution at room temperature with pH = 3.0. The single-crystal X-ray analysis has revealed that 1 crystallizes in monoclinic space group P21 / n with a = 8.4853 (8), b = 13.1520 C = 14.3866 (12) ?,? = 102.629 (3) o, V = 1566.7 (3)? 3, C28H26Cl2CuN6O12, Mr = 773.00, Z = 2, Dc = 1.639 g / cm3, = 0.942 mm-1, the final R = 0.0438 and wR = 0.1214 for 3165 obser- ved reflections with I> 2σ (I). X-ray analysis shows that compound 1 has unsymmetric chelation of dafone with one Cu-N bond being much longer than the other. Coordination geometry of Cu is a highly distorted octahedron and the whole structure is stabilized by π-π stacking and static attractive forces from [ClO4] - anions. Based on the crystal data, quantum chemistry calculation at the DFT / B3LPY level was used to reveal the electronic st ructure of 1.