A new binuclear Cu (II) complex, Cu2L2 (NO3)4 (3) has been synthesized via complexation of Cu(NO3)2·3H2O with coumarin -3- formyl - (3- (aminomethyl) pyridine (L). The crystal structure of L and the complex (3) have been determined by single-crystal X-ray diffraction. The molecular units of L are linked into one dimensional parallel to the b direction via N–H⋯O and C–H⋯O hydrogen bonds. The Cu (II) complex (3) has a 2D supramolecular structure because of the C–H⋯O and C–H⋯N hydrogen bonds. The Hirshfeld surface analysis 41 was performed to provide further insight into the packing and intermolecular contacts of 3. DFT calculations are performed to show that the BS singlet state of the complex (3) is the ground state and to investigate the bonding situation of it. A new coumarin derivate coumarin -3- formyl - (3- (aminomethyl) pyridine) (2) and its dinuclear copper (II) complex Cu2L2(NO3)4 (3) have been synthesized and structurally determined. DFT calculations are performed to show that the BS singlet state of the complex (3) is the ground state and to investigate the bonding situation of it. Display omitted •A new kind of binuclear Cu (II) complex based on coumarin-amide was synthesized.•The crystal structure of this compound was measured.•DFT calculations show that the BS singlet state of 3 is the ground state and to investigate the bonding situation of it.