1：Experimental Design and Method Selection:

The study involved synthesizing N-aryl-2-aminoquinolines via nucleophilic aromatic substitution reactions between 2-chloroquinoline and various anilines, followed by investigating their optical and fluorescence properties in solvents of varying polarity (toluene, ethyl acetate, ethanol). Theoretical models include Hammett plots for substituent effects and mechanisms like ESIPT and hydrogen bonding.

2：Sample Selection and Data Sources:

Compounds 1-9 were synthesized with different substituents (H, Me, Et, OMe, Cl, F, Br, NO2, OH) on the aniline moiety. Data were collected from UV-Vis and fluorescence spectrophotometry.

3：List of Experimental Equipment and Materials:

Stuart melting point apparatus SMP30, Bruker Avance III NMR spectrometer, Perkin-Elmer 1600 series FT-IR spectrophotometer, Cary 60 UV-Vis spectrophotometer, Cary Eclipse fluorescence spectrophotometer, Agilent 6500 series Q-TOF mass spectrometer, TLC plates (Kieselgel 60 F254), silica gel for column chromatography, pressure tube, chemicals from Sigma-Aldrich or Merck.

4：Experimental Procedures and Operational Workflow:

Synthesis involved heating mixtures of aniline and 2-chloroquinoline in ethanol at 80°C for 6 hours, followed by purification. UV-Vis and fluorescence measurements were conducted at concentrations of 10^-7 to 10^-5 M using quartz cells, with quinine sulfate as a standard for quantum yield calculations.

5：Data Analysis Methods:

Fluorescence quantum yields were calculated using a standard equation. Hammett plots were used to correlate substituent effects. Statistical analysis involved comparing quantum yields and spectral shifts across solvents and substituents.