1：Experimental Design and Method Selection:

The study involved synthesizing two hybrid lead halide compounds using different piperazines to form either perovskite layers or post-perovskite chains, followed by structural and optical characterization to understand the mechanisms of self-trapped exciton formation and photoluminescence.

2：Sample Selection and Data Sources:

Polycrystalline and single-crystal samples of (BAPP)Pb2Br8 and (TDMP)PbBr4 were synthesized using lead metal and specific piperazines (trans-2,5-dimethylpiperazine and 1,4-bis(3-aminopropyl)piperazine) with hydrobromic acid.

3：List of Experimental Equipment and Materials:

Equipment included X-ray diffractometers (Bruker Nonius KappaCCD and D8 Bruker), solid-state NMR spectrometer (Bruker Avance III), photoluminescence setup (Horiba Jobin-Yvon Flurolog 3), time-resolved photoluminescence system (Spectra Physics Hurricane X laser and Hamamatsu streak camera), Raman spectrometers (Horiba Jobin-Yvon T64000 and Bruker multiRAM), UV-vis spectrometer (Perkin lambda 1050), and thermal analysis instrument (Netzsch STA 449F3). Materials included lead metal (Alfa Aesar, 99.95%), piperazines (Alfa Aesar and Sigma Aldrich), and HBr (Alfa Aesar, 48%).

4：3). Materials included lead metal (Alfa Aesar, 95%), piperazines (Alfa Aesar and Sigma Aldrich), and HBr (Alfa Aesar, 48%). Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Synthesis involved reflux heating, hydrothermal methods, and vapor diffusion for crystal growth. Characterization included single-crystal and powder X-ray diffraction, solid-state NMR, photoluminescence measurements at various temperatures, time-resolved PL, Raman spectroscopy, and UV-vis reflectance measurements.

5：Data Analysis Methods:

Data were analyzed using Rietveld refinement for XRD, Arrhenius fitting for temperature-dependent PL intensity, and density functional theory calculations for vibrational modes.