Work

Designing advanced luminescent materials via imidazole incorporation: Integrated experimental and DFT/TD-DFT analysis

Year: 2026

Type: article

Abstract: A new polysubstituted pyridine derivative, 2,6-diimidazol-4-carbazol-3,5-dichloro-pyridine (compound 3), was synthesized by functionalizing the reference molecule 4-(carbazol-9-yl)-3,5-dichloro-2,6-difluoropyridine (compound 2) with two imidazole groups. The structure was confirmed by NMR ( 1 H, 13 C, 19 F), IR, and X-ray diffraction. This modification reduced the optical band gap from 3.45 eV (for compound 2) to 3.12 eV (for compound 3), enhanced thermal stability (decomposition onset from 206 °C to 305 °C), and increased phosphorescence lifetime at low temperature, indicating suppression of non-radiative decay. As a result, compound 3 exhibits bright green-blue emission, making it suitable for optoelectronic applications. Furthermore, density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed to characterize the optoelectronic properties of this newly synthesized molecule in its ground and excited states. By integrating both experimental and theoretical approaches, this study elucidates the photophysical properties induced by the attachment of imidazole groups to the reference molecule (2).

Source: Scientific African

DOI: 10.1016/j.sciaf.2026.e03650