1：Experimental Design and Method Selection:

Hydrothermal synthesis was used to synthesize the compounds by tuning reaction temperature (130°C for compound 1 and 160°C for compound 2). Single crystal X-ray diffraction was employed for structural analysis, and various spectroscopic and analytical techniques were used for property investigations.

2：2). Single crystal X-ray diffraction was employed for structural analysis, and various spectroscopic and analytical techniques were used for property investigations. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Compounds were synthesized from Co(NO3)2·6H2O, H3L (biphenyl-3,4',5-tricarboxylic acid), and NaHCO3 in deionized water. Human breast cancer cells (MCF-7, MDA-MB-231, BT-549) were used for cytotoxicity assays.

3：List of Experimental Equipment and Materials:

Elemental analyzer (Vario EL III), powder X-ray diffractometer (PANalytical X'Pert Pro with Cu-Kα radiation), thermal analyzer (Netzsch STA499C), fluorescent spectrometer (Edinburgh Analytical Instrument FLS920), UV-vis spectrophotometer (Puxi TU-1901), high-pressure mercury lamp (500 W), MTT assay reagents, and various chemicals like Co(NO3)2·6H2O, H3L, NaHCO3, methylene blue, isopropanol, triethylamine.

4：Experimental Procedures and Operational Workflow:

Synthesis involved heating mixtures in Teflon-lined vessels, cooling, filtration, and drying. Photocatalytic experiments involved mixing samples with MB solution, stirring in dark, irradiating with UV light, sampling, centrifugation, and UV-vis analysis. Cytotoxicity assays involved cell culture, incubation with compounds, MTT addition, and measurement of IC50 values.

5：Data Analysis Methods:

Structural data were solved using SHELX-97 program. Photocatalytic efficiency was calculated as 100(1-C/C0)%. Cytotoxicity data were analyzed by plotting viability vs. concentration to determine IC50 values.