Preparation, photoluminescence and antimicrobial activity of loracarbef and its various complexes

This study focuses on the photoluminescence properties of loracarbef (LOR) ligand and its [Zn(LOR) (H₂O)(Cl)]Cl, [Cd(LOR)(H₂O)(Cl)]Cl, [Ni(LOR)(H₂O)(Cl)]Cl, [Pd(LOR)(H₂O)(AcO)]AcO and [Pt(LOR)(H₂O)(Cl)]Cl complexes. LOR and the resulting metal complexes gave an intense emission (where V_max = 376 nm) upon irradiation by Ultra-Violet light. The photoluminescence quantum yields and long excited-state lifetimes of the ligand and its complexes were calculated. The LOR ligand has a photoluminescence quantum yield of 52% and long excited-state lifetime of 4.88 ns. The photoluminescence intensities and quantum yields of the metal complexes dramatically reduced with respect to that of the LOR ligand upon complexation with various metals. The structures of new complexes were characterized using spectroscopic techniques including FT-IR, electronic spectra, ¹H-NMR and mass spectral data. In addition, all complexes were screened for antibacterial activity against several bacteria and yeasts, and results were compared with those of LOR.