The sensorial potentials of the OH-stretching mode: phenols

The OH stretching band of an extended series of phenols has been investigat ed in the apolar solvents CCl4 and CS2. A detailed analysis discloses the s ensorial potentials of the phenolic OH stretching mode as regards to intra- and intermolecular interactions. For the three rotamer classes, PH, PMe an d PtBu, the band parameters, such as peak maximum, half bandwidth and solve nt shift values, ant shown to be linearly correlated with Hammett sigma(p) and pK(a) values. The magnitude of the nu(OH) band shift parameters for aro matic substitution is clearly shown to be correlated with the rotamer type, e.g., shielding of the OH proton. Assignment and rotamer distribution calc ulation is supported by MM3 calculations. This review deals with the sensor ial potentials of the 'free' phenolic OH stretching mode. Insight has prove n to be useful when unravelling weak(er) H-bonding geometries and interacti on mechanisms. (C) 1998 Elsevier Science B.V. All rights reserved.