Application of an amide-modified bifunctional star-shaped triazine derivative in Fe³⁺ ion detection and optical power limiting

A star-shaped triazine derivative (T-TPZ) was synthesized, which was multifunctional for the detection of Fe³⁺ ions and optical power limiting applications. The optical characteristics of T-TPZ were thoroughly analyzed using UV-vis absorption spectra, fluorescence emission spectra, and density functional theory (DFT) calculations. Notably, within the UV-vis range, T-TPZ exhibited several electronic transitions, including n-π*, ¹π-π*, and intramolecular charge transfer (ICT) transitions. Interactions between the amide group of T-TPZ and Fe³⁺ ions initiated an ICT process resulting in fluorescence quenching, with a detection limit of 2.73 × 10⁻⁷ M. Remarkably, the fluorescence intensity decreased by 90% within 30 seconds, highlighting the high selectivity and sensitivity of T-TPZ. Job's plot analysis revealed a coordination stoichiometry of 1 : 3 between T-TPZ and Fe³⁺ ions. Variations in the T-TPZ concentration within PMMA films were also examined to further explore optical power limiting properties, demonstrating new insights and directions for the development of multifunctional materials.