The O–H⋯π hydrogen bonded phenol–benzene(+) radical cationic dimer: a gradient-corrected density functional study

A B3LYP and mPW1PW91/6-31++G(d,p) study of phenol–benzene(+) radical cation was performed, revealing an existence of T-shaped O–H⋯π hydrogen bonded minima at both PES-s, with center-of-mass separation of 5.087 Å (B3LYP) and 4.970 Å (mPW1PW91) and the interplanar angle between monomeric units of 89.9° and 89.4° (at B3LYP and mPW1PW91 levels correspondingly). Calculated anharmonic O–H vibrational frequencies on the basis of one-dimensional DFT vibrational potentials reproduce excellently the experimentally measured ν(OH) frequency shift upon this interaction. According to CFP-like calculations, most of the interaction energy (47.09 and 49.64 kJ mol−1 at B3LYP and mPW1PW91 levels correspondingly) is of electrostatic origin.