Tuning Photoluminescence and Emission Polarization in Metal–Curcumin Complexes via Magnetic Fields

High Resolution Image Download MS PowerPoint Slide 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.