1：Experimental Design and Method Selection:

Condensation chemistry was used to form Schiff base (SB) ligand with anthracene 9 carbaldehyde and 3,4 diaminopyridine, incorporating Er, Pr, and Yb rare earth metals to form SB complexes.

2：Sample Selection and Data Sources:

The SB and metal complexes were synthesized and characterized using elemental analysis, NMR, SEM, FTIR, TG-DTG, UV–vis, and fluorescence spectroscopy.

3：List of Experimental Equipment and Materials:

Carlo Erba 1108 elemental analyzer, Bruker advance DPZ-300 spectrometer, FEI Quanta 250 SEM, JASCO spectrophotometer, PCT-2A thermo balance analyzer, Perkin Elmer LS25 UV–vis spectrophotometer, Perkin Elmer LS45 fluorescence spectrophotometer.

4：Experimental Procedures and Operational Workflow:

The SB was synthesized by stirring a methanol solution of 3,4 diaminopyridine and 9 anthraldehyde, followed by the addition of lanthanide nitrates to form metal complexes. The complexes were characterized and their antibacterial activity was tested.

5：Data Analysis Methods:

The antibacterial activity was measured by well diffusion method, and the results were analyzed in terms of zone of inhibition.