Related Experiment Video
Updated: Aug 5, 2026

Enhanced Photoluminescence of Curcuma longa Extracts via Chitosan-Mediated Energy Transfer for Textile Authentication Applications
Published on: December 22, 2023
Tuning Photoluminescence and Emission Polarization in Metal-Curcumin Complexes via Magnetic Fields
Pedro Henrique Dondori Zaramella1, Bruno Souza Zanatta1, Giovani Bortolini de Oliveira1
1Physics Institute, Federal University of Uberlandia, 38400-902 Uberlandia, Brazil.
None:
Curcumin complexes with Zn-(II), Pb-(II), and Ca-(II) were synthesized and spectroscopically characterized, with emphasis on magnetic field modulation of photoluminescence and emission polarization. Raman and FTIR analyses confirm coordination through the enolized β-diketone moiety. UV-Vis absorption and photoluminescence spectra exhibit red shifts, 426-432 and 525-534 nm, respectively, indicating metal-ligand interactions and charge-transfer contributions. Vibronic line shape analysis reveals changes in the electronic gap, electron-vibrational mode coupling, and spectral line width, with significant narrowing for the Zn-(II) complex, consistent with increased molecular rigidity. Measurements using the emission ellipsometry technique demonstrate that an external magnetic field modulates both the intensity and polarization of the emitted light of curcumin in a coordination-dependent manner, with the strongest response observed for the Zn-(II) complex. These results show that metal coordination combined with magnetic fields provides an effective strategy to tune photoluminescence and emission polarization in curcumin-based systems, highlighting their potential for photonic and magneto-optical applications.
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Variables Affecting Phosphorescence and Fluorescence
Photoluminescence: Applications

