DFT theoretical, synthesis, X-ray diffraction and IR studies on new dinuclear copper macrocyclic complexes

Two symmetric dinuclear copper (II) macrocyclic complexes ([Cu2L](ClO4)2 and [Cu2L′](ClO4)2) were unexpectedly obtained by the cyclocondensation between N,N′-bis(3-formyl-5-n-butylsalicylidene)ethylenediimine and 1,3-diaminopropane in the presence of copper (II) perchlorate and characterized by some physical methods. Both complexes were determined by X-ray diffraction techniques. DFT theoretical calculation was used to discuss the structure and to assign the IR spectra of the cation of the complex ([Cu2L](ClO4)2, the complete vibration spectral analysis was performed. A good agreement is obtained between DFT theoretical calculation results and the experimental data for the complex ([Cu2L](ClO4)2.