حمید رستمی دانا

n this research study, DFT-TDDFT calculations were used to analyze the electronic structure and simulation of the electronic absorption spectrum of the dinuclear cobalt(II) complex with II–II oxidation state of 20-membered N4, binucleating macrocycle derived by a cyclic [2 + 2] condensation of isophthaldialdehyde with 1,3-diaminopropane using CAM-B3LYP hybrid-DFT functional and 6-311+G(d,p) basis set. The structure of the [Co2LBr2OH]Br complex was optimized using density functional theory for all of the possible spin states of the complex. On the basis of the DFT results for spin 1, 3, 5, and 7 spin states, there is a clear thermodynamic preference for septet spin multiplicity even at 0 K, which exhibits two independent cobalt centers with tetrahedral coordination geometries, as can be concluded from their tau parameters. The TDDFT calculation demonstrates transitions from the β-spin HOMOs having mainly dxy, dxz character to the β-spin LUMOs with dominant Co dz2, dyz and dx2_y2 character.