The new heterometallic, mixed-valence compound [Cu 2 (bpy) 4 (C 2 O 4 )][(VO) 2 O(bpy) 2 (C 2 O 4 ) 2 ] 2 ·10H 2 O has been synthesized, its crystal structure determined and its spectroscopic characterization accomplished by means of solid-state vibrational (far and mid FTIR) spectroscopy. The title compound crystallises in the triclinic system, space group P1 (No. 2) [a = 13.488(5) Å , b = 14.160(6) Å , c = 15.829(9) Å , α = 87.22(2)°, β = 66.33(2)°, γ = 64.49(2)°, V = 2471(2) Å 3 , Z = 1]. The compound consists of the cationic binuclear copper(II) complex [Cu 2 (bpy) 4 (C 2 O 4 )] 2+ , two anionic binuclear mixed