1：Experimental Design and Method Selection:

The study involved the synthesis of a pyrazoline derivative, structural characterization using NMR, FT-IR, elemental analysis, and X-ray crystallography, optical studies including UV-Vis and fluorescence spectroscopy, and molecular modeling using DFT methods. The fluorescence quenching mechanism was analyzed using the Stern-Volmer equation.

2：Sample Selection and Data Sources:

The compound 1,3-diphenyl-5-{4-[(4-vinylbenzyl)oxy]phenyl}-4,5-dihydropyrazole was synthesized and used as the sample. Solvents such as toluene, chloroform, DMSO, and carbon tetrachloride were used for optical measurements.

3：List of Experimental Equipment and Materials:

Equipment included a MEL-TEMP capillary melting point apparatus, PerkinElmer 2400 Series II CHNS/O system, Bruker Avance 400-MHz spectrometer, FT-IR Bruker Vertex 70 instrument, SPECORD 210 Plus Analytik Jena spectrophotometer, Perkin-Elmer LS 55 spectrofluorometer, Oxford-Diffraction XCALIBUR E CCD equipment, and computational resources with Gaussian09 and GaussView 5 software. Materials included chemical reagents and solvents from Sigma-Aldrich.

4：Experimental Procedures and Operational Workflow:

Synthesis involved Williamson ether synthesis, Claisen-Schmidt condensation, and condensation with phenylhydrazine. Optical measurements were conducted in various solvents with specific concentrations and excitation wavelengths. Molecular modeling included geometry optimization and TD-DFT calculations.

5：Data Analysis Methods:

Data were analyzed using NMR spectroscopy, UV-Vis and fluorescence spectrometry, X-ray crystallography with CrysAlis and Olex2 software, and computational methods with Gaussian09 for DFT and TD-DFT calculations, including the Stern-Volmer equation for quenching analysis.