Enhanced Optoelectronic and Biological Potential of Virescent-Glowing Terbium(III) Complexes with Pyrazole Acid

Abstract

A series of five virescent color emitting terbium(III) complexes is fabricated by a cost-effective and eco-friendly solution precipitation technique with the utilization of 1-(4-methoxyphenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid (L) as a primary ligand and highly conjugated nitrogen donor secondary ligands such as bathophenanthroline (batho), 5,6-dimethyl-1,10-phenanthroline (dmph), 1,10-phenanthroline (phen) and 2,2-bipyridyl (bipy). The elemental compositions of complexes are examined through energy dispersive x-ray and elemental analyses, whilst the binding nature of ligand with terbium(III) ion is confirmed using proton nuclear magnetic resonance and infrared spectroscopy. The band gap energy (E_g) of complexes is found in the range of 3.85–3.34 eV as evaluated from diffuse reflectance spectral data. The significant thermal stability of these luminescent materials (157°C) demonstrates their key role as virescent component in white organic light emitting diodes. The intense emission and decay time of complexes are explored through photoluminescent study. The good color purity and Commission International De I’Eclairage color coordinates promise the enhanced performance of these materials in lighting appliances. The sensitization phenomenon highlights the role of ligands in increasing the luminescence intensity of complexes. The biological assessment indicates that the complexes are potent antimicrobial and antioxidant agents. The aforementioned features extend the field of applications of complexes in laser technology and optoelectronic devices.