Synthesis, crystal structure and excellent photoluminescence properties of copper (II) and cobalt (II) complexes with Bis(1[(4-butylphenyl)imino]methyl naphthalen-2-ol) Schiff base

Copper (II) and Cobalt (II) metal complexes (4a- and 4b-complexes) using Schiff base ligand 1-[(4-butylphenyl)imino]methyl naphthalen-2-ol (3) have been synthesized. The single crystals of Copper (II) and Cobalt (II) complex phosphors were grown and characterized by Fourier-Transform Infrared (FT-IR), single crystal X-ray diffraction (XRD), SEM (Scanning Electron Microscope) and EDS (Energy Dispersive X-ray spectroscopy). Photoluminescence study of the phosphors revealed the presence of excitation peaks at 333 nm and 360 nm for 4a-complex (λemi = 495 nm) and excitation peaks at 300 nm and 360 nm for 4b-complex (λemi = 496 nm). The calculated CCT values of the complexes pointed out that these materials can be used to obtain cold white light from the light emitting devices. Diffuse reflectance spectra (DRS) showed the measured band gap energies of 1.78 eV and 1.44 eV for Cu (II) and Co (II) complexes, respectively. It is concluded that the 4a- and 4b-complexes become white and blue green light emitting diodes respectively and will be useful in the development of strong electroluminescent materials.