Synthesis, characterization, and photoluminescence properties of Cu(II), Co(II), Ni(II), and Zn(II) complexes of N-aminopyrimidine-2-thione

This research concentrates on the preparation, characterization, and photoluminescence properties of new Co(II), Ni(II), Cu(II), and Zn(II) complexes of N-aminopyrimidine-2-thione. The ligand and metal complexes were characterized by elemental analysis and spectroscopic studies such as IR, UV/Vis, API-ES, NMR, fluorescence, and magnetic susceptibility measurements. The ligand and the resulting metal complexes gave intense emissions (lambda(max) = 408 nm) upon irradiation by ultraviolet light. The photoluminescence quantum yields and long excited-state lifetimes of the ligand and its complexes were calculated. The ligand had photoluminescence quantum yields of 36% and long excited-state lifetimes of 3.40 ns. The photoluminescence intensities and quantum yields of the metal complexes changed upon complexation with various metals. These novel complexes may be of interest as organic emitting material for electroluminescent devices.