The specific interaction between parafluorophenol and alkylbenzenes in n-hexane has been studied using infrared spectrometry. The absorption spectra of different donor-acceptor couples exhibit bands in the region 3600–3500 cm−1which are characteristic for the formation of hydrogen bonded complexes OH…eπ. The observed frequency shifts are between 67 and 92 cm−1, and the values of the complexation constant range from 0.41 to 1.51 dm3mol−1. The values of the free enthalpy of interaction -ΔG are situated between -2.22 and+1.05 kJ.mol−1, while the affinity ratio varies from 3.08 to57.98.