Abstract: Using FTIR the OH frequency shift Δv_OH for a series of tertiary butyl phenols (C₆H₅OH, 4-t-(CH₃)₃CC₆H₄OH, 2-t-(CH₃)₃CC₆H₄OH, 3,5-Di-t-[(CH₃)C]₂C₆H₃OH, 2,6-Di-t-[(CH₃)₃C]₂C₆H₃OH] in reaction with several nitrogen and oxygen Lewis bases have been measured. The accuracy and reliability of the Δv_OH are pretty good. According to the relationship between Δv_OH and the helat of adduct formation ΔH, the latter is predicted. The calculated ΔH values were shown to be in reasonable agreement with experimental data.

Key words: Organic phenols, Lewis, base Frequeney shift, Enthalpy FTIR