Intramolecular interactions in ortho-substituted phenols: survey of DFT-B3LYP calculated data

A survey is given of theoretical and experimental data of intramolecular hydrogen bonds in 47 different ortho-substituted phenols. The sample includes various kinds of O-H .. Y interactions (Y = N, O, S, F, Cl, Br, I, C = C, C equivalent to Z(Z = C,N)) and covers theoretical data (bond distances and angles, Q(Y) partial charges, Y(OH) frequencies) of 48 compounds as calculated at the DFT-B3LYP level of theory using 6-31G(d,p), 6-311G(d,p), and DZVP basis sets, along with experimental IR nu(OH) frequencies. The relevance of the calculations is demonstrated by the good agreement between experimental and theoretical nu(OH) frequencies. The bond strength sequences obtained for several series of similar or of systematically related compounds are discussed and interpreted in terms of hydrogen bond distances, partial charges, Van der Waals' radii and a-electron densities of the Y-proton accepters. (C) 1998 Elsevier Science B.V. All rights reserved.