1：Experimental Design and Method Selection:

The study involved synthesizing two symmetric imidazole-substituted cyanostilbene derivatives (TPIA and PPIA) via Knoevenagel condensation reactions. Photophysical properties were studied using UV-vis and PL spectroscopy, AIE properties were investigated in acetonitrile/water mixtures, thermal stability was assessed via TGA and DSC, electrochemical properties were measured using cyclic voltammetry, and EL devices were fabricated and characterized.

2：Sample Selection and Data Sources:

Samples included TPIA and PPIA molecules synthesized in the lab. Data were obtained from spectroscopic measurements, thermal analyses, electrochemical tests, and device performance evaluations.

3：List of Experimental Equipment and Materials:

Instruments included NMR spectrometer (Bruker Ultrashield 400 MHz), MALDI-TOF mass system (Kratos), UV-vis spectrophotometer (Hewlett Packard 8453), PL spectrophotometer (Perkin Elmer LS 55B), optical fiber spectrophotometer (Maya 2000Pro), integrating sphere (C-701, Labsphere Inc.), TGA (PE TGA-6), DSC (Perkin Elmer Pyris Diamond), cyclic voltammetry workstation (BAS CV 50W), single-crystal X-ray diffractometer (Bruker APEX DUO CCD Area Detector), and EL measurement setup with PR650 spectra scan spectrometer and Keithley 2400 source meter. Materials included starting chemicals from Dieckmann or Aldrich Chemical Co.

4：Experimental Procedures and Operational Workflow:

Synthesis involved refluxing and purification steps. Photophysical measurements were conducted in THF and solid state. AIE studies used acetonitrile/water mixtures. Thermal analyses were performed under nitrogen. Electrochemical measurements used Pt and Ag/Ag+ electrodes. X-ray diffraction was done at 173 K. Device fabrication involved vacuum deposition on ITO substrates, with layers including HAT-CN, NPB, TCTA, emitting layer, TPBi, and LiF/Al.

5：Data Analysis Methods:

Data were analyzed using standard spectroscopic techniques, thermal analysis software, electrochemical methods, and device performance metrics (efficiency, luminance, etc.). Structural refinement used SHELXL-2014/7.