Plot of Stokes’ shift (Δν) against the Reichardt
solvent polarity parameter, ET(30). 1
→ 5 for nonpolar and polar aprotic solvents: n-hex, DOX, CHCl3, THF, and ACN; 6 → 9 for hydrogen-bonding
solvents: BuOH, EtOH, MeOH, and H2O for (a) DANP0, (b) DANP1, (c) DANP2, and (d) DANP3 molecules.