AbstractN‐(4‐nitrophenyl)‐L‐proline (2) has been obtained by a nucleophilic aromatic substitution reaction of 4‐fluoronitrobenzene with L‐proline. The corresponding amide derivatives 3–5 have been synthesized by peptide coupling of 2 with different amino acid derivatives and chiral amines. Solvatochromism of the long‐wavelength UV/Vis band in the electronic absorption spectra of the compounds 2–5 has been studied and analyzed using the empirical Kamlet–Taft solvent polarity parameters π* (dipolarity/polarizability), α (hydrogen bond donating ability), and β (hydrogen bond accepting ability). Reasonable Kamlet–Taft solvatochromic correlations (r > 0.95) were established for the three amide derivatives 3–5 in a range of common solvents and three room temperature ionic liquids (RTILs). The UV/Vis absorption of the 4‐nitroaniline derivative 2 showed a hypsochromic shift with increasing concentration due to intermolecular hydrogen bonded aggregate formation in protic solvents, which is not observed for compounds 3–5. Copyright © 2008 John Wiley & Sons, Ltd.