1：Experimental Design and Method Selection:

The study involved synthesizing four Eu(III) complexes using different primary ligands (PCA, PCAO, PDCA, PM) and an ancillary ligand (DMBP) to enhance luminescence via antenna effect and synergistic complexation. Characterization was done using FT-IR, UV-vis, PL spectroscopy, XRD, SEM, TGA, and lifetime measurements. Anion sensing was performed through titration with various anions in DMSO.

2：Sample Selection and Data Sources:

Complexes were synthesized from commercially available chemicals (Sigma-Aldrich, Merck). Anion solutions were prepared from tetrabutylammonium salts. Samples were analyzed in solution or solid state as appropriate.

3：List of Experimental Equipment and Materials:

Equipment included Perkin Elmer Thermogravimetric Analyzer, Shimadzu IR Affinity 1S Spectrophotometer, PAN Analytical X-ray Diffractometer, Hitachi U-2900 Spectrophotometer, Varian FT-Raman spectrophotometer, Varian Cary Eclipse Fluorescence Spectrophotometer, Edinburgh instrument for lifetime, Carl Zeiss EVO 18 SEM. Materials included EuCl3, ligands, solvents (methanol, DMSO), and anion salts.

4：Experimental Procedures and Operational Workflow:

Synthesis involved refluxing mixtures of ligands and EuCl3 in methanol at 70°C for 4 hours, followed by filtration and drying. Characterization techniques were applied as per standard protocols. Anion titrations were done by adding incremental equivalents of anions to complex solutions and measuring changes in UV-vis and PL spectra.

5：Data Analysis Methods:

Data were analyzed using equations for quantum yield, lifetime decay (single exponential fitting), and fluorescence quenching degree (FQD). Statistical analysis included Stern-Volmer plots for quenching mechanisms.