The Cu(II) complex compound (Cu(C11H17N3O3)(2)CL2(H2O)(2)) was synthesized from reaction between the copper(II) chloride dihydrate and the 4-ethoxy-2-methyl-5-(4-morpholinyl)-3(2H)-pyridazinone. The Cu(II) complex compound in octahedral geometry was characterized using elementel analysis, FT-IR and UV-Vis. spectroscopic techniques. The molar conductance and magnetic susceptibility of the Cu(II) complex were experimentally investigated to confirm octahedral geometry. The quantum chemical computations for molecular geometric parameters, vibrational wavenumber, UV Vis. parameters, HOMO-LUMO investigations and NBO analysis of the complex compound were performed by using UHSEh1PBE functional in DFT method at the LanL2DZ basis set. The vibrational analysis was performed to determine metal-ligand bond and ligand vibrations. The HOMO and LUMO analyses were investigated to understand charge transfers and electronic transitions in the complex. The electronic configuration, natural charge and coordination environment of the Cu(II) metal ion was investigated via NBO analysis. The experimental results were compared with computed data. (C) 2018 Published by Elsevier B.V.