Mid- and near-infrared study of the hydrogen-bonded complexes between pentachlorophenol and proton acceptors

The mid- and near-IR spectra of hydrogen-bonded complexes involving pentach lorophenol (PCP) and organic bases (acetonitrile and O-bases) were investig ated in carbon tetrachloride solution. The complex between PCP and acetonit rile (ACN) was studied at different ACN: CCl4 concentration ratios. The fre quency of the simultaneous transition nu(OH...N)+ nu(C=N) depends on this c oncentration ratio. The anharmonicity of the nu(OH...N) vibration is discus sed as a function of the Onsager parameter of the medium. The anharmonicity of the nu(OH...O) vibration of complexes involving PCP and O-bases increas es with increasing enthalpy of complex formation. Other near-IR observation s are discussed. Copyright (C) 2000 John Wiley & Sons, Ltd.