Copper(II) complexes of azo rhodanine (1–3) were prepared and characterized by elemental analyses, IR spectra, X-ray diffraction, thermogravimetric analysis (TGA), molar conductance and magnetic susceptibilities as well as mass spectra. The IR spectra showed that the ligands act as a monobasic bidentate coordinating via nitrogen atom of − N = N − group and oxygen atom of enol form. The X-ray diffraction pattern of complex (2) is polycrystalline phase. Quantum chemical parameters and geometric structural of the complexes were theoretically computed and the results were studied. The alternating current conductivity (σ_ac) and dielectric properties of Cu(II) complexes (1–3) were investigated in the frequency range of 0.1–100 kHz and temperature range of 303–500 K. The values of thermal activation energies of electrical conductivity (ΔE₁ and ΔE₂) for Cu(II) complexes are calculated and discussed. It was found that the electrical conductivity depends on the nature of substituents of the complexes. The correlated barrier hopping (CBH) is the dominant conduction mechanism for all complexes.